hello 

im pretty new to d&d as a whole and enjoy looking through the information provided (mainly for hypothetical world building - never actually played a game) 
and i had a few questions about goblinoids and their pantheon of gods (amongst others)

if anyone could provide any assistance with any of the following questions
it would be appreciated 

1) where would be the best place to find information on the queen of air and darkness?? (i think it was)
2) are orcs, kobolds, mongrelfolk counted as goblinoids or are they all in their own separate groups??  
3) do varags, dekanter goblin, gurnung goblin, grood goblin or bhuka goblins exist in dnd 5e?? (unsure if they from other sources)
4) do the deities Kikanuti, Gapnagurnung, Meriadar and Stalker (the dreaded) exist in dnd 5e?? 
5) do the deities of a pantheon need to be the same species as those who worship them?? and do pantheons from different species ever work together?? 
6) what is/are the tanar'ri?? and could they be used as primitive/distorted/mutated goblinoids??
7)  where would be the best place to find information on the following deities: Diirinka (derro), Diinkarazan (derro), Ilsensine (Illithid), Psilofyr (myconid) and Pandorym (elder evil)??
8) are the Derro dwarfs or can i make them a type of half goblin?? they seem very similar personality-wise 
9) can a deity pretend/disguise themselves as a different deity?? some seem to have very similar stories/histories/preferences 
10) who did Maglubiyet control before taking over the goblinoid pantheon??

and lastly 
11) would the following be possible:  (general plotline - i guess)

Luthic (orc deity) and Kikanuti (goblin deity) work together to remove Gruumsh (orc deity) and Maglubiyet (goblin deity) from thier leadership roles to prevent the rising of Stalker (Elemental entity/Goblinoid deity) to the strongest amongst the goblinoid pantheon by stopping the needless deaths of gobliniods.

Luthic (orc deity) found out about Ilnevals (orc deity) affections bringing him aboard and got her son Bahgtru (orc deity) to aid her against Gruumsh (orc deity) and Maglubiyet (goblin deity).

Kikanuti (goblin deity) work with Nilbog (goblin deity) and Bargrivyek (goblin deity) to gain the aid of Khurgorbaeyag (goblin deity), Gapnagurnung (goblin deity) and the iron one (goblin deity).  

in turn Khurgorbaeyag (goblin deity) convinced Hruggrek (bugbear deity) to bring the other bugbear deities Grankhul, Skiggerat and Stalker into the plan.

Hruggek (bugbear deity) reveals a pact with Kurtulmak (kobold deity) and ends Bargrivyeks (goblin deity) invasions of Draukari, in return Kurtulmak (kobold deity) brings in the other kobold deities Dakarmok and Gaknulak.

Meriadar (mongrelfolk deity) seeing the other goblinoids working together joins the pantheon at the annoyance of Stalker (bugbear deity) dispite Skiggerat (bugbear deity) convincing Stalker (bugbear deity) that is was a good thing and would lead to him becoming more powerful in the long-run via more goblinoid deaths

with the unification of the goblinoid races Nilbog (goblin deity) was pieced back together/resurrected as a deity of the goblinoid pantheon.

Maglubiyet dies 
Gruumsh dies
Nomog-Gaeya unsure about, possibly falls in line or goes into hiding/dies 
Shargaas unsure about, possibly finds kinship amongst the bugbears or goes into hiding
Yurtrus unsure about, possibly falls in line or goes into hiding/dies - maybe ties to pandorym as the new big bad

unsure if any of that make any sense but would appreciate any information, corrections or assistance anyone could provide

#1, Romeo and Juliet Act I, scene 4.

#2, The Monstrous Manual gives Orc, Kobold, and Mongrelfolk as all having the humanoid creature type. What that means, and whether it remains true in the world of your game are mostly up to you and your worldbuilding.

#3, 5e embraces the convention that existing material can be reflavored to fit new concepts. All those creatures exist if you want them to exist and if your worldbuilding has a reason for them to exist. They would likely use the goblin's statistics with changes which reflect the role of these creatures in your world.

#4, I've never heard of them. The rest is between you, your worldbuilding, and your lore drops.

#5, To your question, a question. Are you interested in addressing colonialism as one of the themes in your game?

#6, Tanar'ri was a word to replace "demon" back when D&D was the target of moral panics in the 80's. In the Great Wheel cosmology it means any resident of the Abyss. Whether that remains true in your world is between you and your worldbuilding.

#7, Pathfinder 1e (there won't be a lot).

#8, Yes. To both parts of your question. In Forgotten Realms' Aber-Toril, they are corrupted deep gnomes. Whether that remains true in your world is between you and your worldbuilding.

#9, Of course they can if the story benefits from that development. Many D&D cosmologies use the "gods need belief" trope, meaning that it works against a god's interests to go around in disguise unless they can take credit for what they did after the fact. Whether that remains true in your world is between you and your worldbuilding.

#10, Whoever you want her to have controlled. It's your story.

#11, That's backstory. Plot is what happens when PCs respond to these developments. Sounds like it could be cool. You might want to ask players to choose goblinoid races so they have a stake in all this divine mucking around.

thank you, much appreciated

as for the colonialism part - i havent given that much thought to be honest, however theres likely to be some aspects of it somewhere in the world im piecing together,
whether the gobliniods are for or against it (apart of or outside it) im unsure at this stage 

i just have a little soft spot for the goblinoids and have always been curious what they would be capable of if for example:
if they learned the companionship/stealth similar to the kobolds
or the crafting/mining of the dwarves
or even the attitude/grace of the elves  

Question #1 Where would be the best place to find information on the Queen of Air and Darkness?

Have you researched the Gloaming court? Realize the Queen of A&D is new, and not many have taken the opportunity to write much about her, but from the little the WotC put out, it reminds me of Maleficent rather superficially. Either way, this topic is probably open to Ghost writers at the moment, so have fun with what you like.

Question #2. Are orcs, kobolds, mongrelfok counted as goblinoids or are they all in their own separate groups?

The only reason anyone would really ask this question is if you had a game mechanic that only targeted or affected goblinoids. If this is your goal for this inquiry, then you are in luck. {Your game, you set your mechanics}

However, I would say absolutely not. Kobolds are of Dragon ancestry in a very loose way. But they do bow down to dragons and their kin. Kobold is the lowest lowest form of the Dragon species. Google “What they don’t tell you about kobolds – D&D” MrRhexx did a good job on that video.

Orcs, I would suggest to Google “What they don’t tell you about Orcs”. Another great video by MrRhexx they have more in common with Ogres and Orogs than with goblins. And Orcs have no hang-ups about racial purity according to accepted lore.

Mongrelmen or mongrelfolk was the original D&D answer to the body horrors associated with hybrids and cross breeding of fantasy species. From back in 1E I remember these made for pitiful NPC’s that were beggars or hermits that society threw away. A good deity to look up here is the “Hidden God”. And evil wizards are known to make a sub-type called Mongrelman Infiltrator which are just weaker Dopplegangers.

It is interesting to see your interest into goblin origins and deities. I don’t meet many who know about Maglubiyet, the God of War and Battle. He is a lesser deity under Bane. His feelings of goblinoids is no different than how a barbarian sees a random battle axe. He will use his possession when he feels like it. Which made me smile when I read the question if Orcs were considered Goblinoid, with Maglubiyet’s hatred of orcs and his relentless war against the petitioners of Gruumsh. AD&D 3.5E had a supplement called “Sandstorm: Mastering the Perils of Fire and Sand”. This would be more to your liking. Also “Deities and Demigods” was another amazing supplement which is sure to inspire.

1) Queen of air and darkness -> She is mostly associated with the fey courts, especially the unseelie court in some places, so anywhere talking about the unseelie court Queen, or feywild/shadowfell leaders. Another example, in Midgard Campaing Setting (Kobold Press) there is an elven goddess that claims that title (Sarastra, mistress of Air and Darkness), she's mostly the "elven/fey" goddess of the shadowfell or dark fey/elves, but also in that setting gods tends to have many "faces/masks" depending on which country worships them.

2) It depends on what you want, all of them tend to be Humanoids with their own subtype different to goblinoids, dont know about mogrelfolk. Goblinoids mostly contain: Bugbears, Hobgoblins and Goblins, with many other similar beings attached (mostly psionic or their different brethen from the underdark).

3) Havent seem them yet. Maybe a setting specific book or 3rd party.

4) Deities depend mostly in the setting they are used. In these case, if you have information from older editions is easy to adapt them to 5e and your campaing, without much change (or a lot if you want to, just assign a logical domain for clerics).

5) It depends. Most general pantheons of settings have "preferred or more common" worshipers for each deity but are not required to be of a particular race., and their appearance tends to be random (its basically how people imagine them). The common denominator of a Racial Pantheon is that a particular race tends to worhip them exclusively and for that the God takes a form related to that race (but its not a requirement, again they are gods, they take any form they want.). Normally most races except Humans have a "Creator God " or "Originator God" that tends to be the Main god of a pantheon (think of: Corellon, Moradin, Kurtulmak, Garl Glittergold, Maglubiyet, Gruumsh, Yondalla and the like). In the end, it depends how you handle it in your own world, and what "rules" apply to religion, worship and gods.
As for the fact that 2 gods of different races work together... sure, if you want to. Gods goals tend to be twofold: to upgrade their worship base to increase in power/station, to gain or take/steal a new portfolio/domain to increase worshipers. In almost every God description of many settings and systems it tends to have a space dedicated to gods relationships, friends and enemies (mostly on wikis, of course). Mostly Gods join together because a goal aligns with each other.

6) Tanar'ri are a race or type of Demon from the Abyss, currently the "dominating species". At least in DnD that is their general description, there are other types of Demons or Abyssal creatures, like the Obyriths in some editions. The Ghoul King  (a lesser demon lord and tanar'ri) its commonly connected as the lord of intelligent ghouls, as is Baphomet for many "chaotic evil" minotaurs and beast.

7) Wikis mostly. Older edition books. I think Ilsensine could be on any underdark or aberration related books (Lords of Madness in Dnd 3.5ed is a good book for him).

Pandarym: wikis, or try D&D 3.5 Elder Evils. There is an entire chapter for him.

8) Normally, yes derros are a kind of underdark dwarf (as are the duergar). But do as you want for your world. There is an underdark Goblin race somewhere i think.

9) Short asnwer: Yes they can. Its a common trope that believes that the gods are the same but take different names on different settings (and some take the same name, see how wotc describes bahamut and tiamat in the different settings in Fizban's Treasury of Dragons).
On some settings, like the one I mentioned before Midgard, the main appeal is that all the gods have posible "masks" or "personifications", and that every country sees them in a different way or believes they just have different names: in the crossroads people believe in Rava, but in seven cities she's called Ariadne, and maybe in the North she is frigga or freya, and etc... Even the domains and portfolios may be different in each "mask" or "personification".

In other parts, I think Cyric took some other god portfolio and name from some time, while still having its own. Its a common or possible trope, and depends on the objective of the god or narrative the reasons behind.

10) can't answer, always have believed Maglubiyet was the main goblin god forever. Maybe you can anwser that yourself jeje.

11) Like others have said. its a plotline for your world or its History. Off course is possible, if you want that to happen. The most important part would be, how the world is affected by each of those plot points in time (Gods are inmortal, their plans don't have to be inmediate), and how mortals influence, if they can indeed influece any point, or are influenced by them, how their daily lives are going to be affected when the changes begin to happen. Answer yourself that, and you have a story brewing.

Hope it helps a little, adding to what others have said before.

I’m curious; how did it go?