I have added a race to my collection (didn't create it), but there is something about it that I don't like, I want to make a copy of it (IIRC I can't, so I'd have to make my own and copy and paste stuff, I get that). Disclaimer: If I do this, I will not be publishing it, because that would be really sh*tty of me to do; it would just be for me (and the ppl in my campaigns I guess)

This race, "Demigod", has a feature called Parent's Assistance which says "You may call on your parent for assistance. The next time you roll a d20, you gain advantage on that roll. However, your parent prefers you walk your own path and will not assist you again until the next dawn". Now, that's something that I personally wouldn't have, but it's what the creator wanted to race to have & could make for more enjoyable gameplay for my players, so it's fine to stay.
The big issue I do have with it though is it's making every ability get the little {A} for advantage (link to one of my character sheets for reference); which 1) it doesn't really and could lead to issues where someone rolls w/ advantage when they don't really have it, and 2) makes it hard to know when you actually do have advantage. Presumably,  the way to prevent this is to not actually put anything in there that makes the feature do anything (maybe give it a charge so that you can check that you've used it), but I wanted to ask to make sure.

Secondly, I'm running into an issue with its' subraces (and frankly, every other race that has subraces) that I'd like to avoid if possible. The race has 13 subraces; these subraces appear under the main race if I click on it, under the drop-down menu for Aasimar (for this race in particular, not every race w/ subs appears under an official race), and also each individual subrace shows up by itself as if it were a standalone race. How in the Nine Hells do I avoid that from happening?

For your first problem, temporary effects such as that are not supported, so it would be best to simply implement it as plain text without any modifiers. Please see the Subclasses & Species FAQ #2 for more info.

For your second problem, I’m afraid you’re out of luck. Please see the Subclasses & Species FAQ #5 for more info.

Quote from AzathothBazathoth >>

Is there anyway to create a custom weapon, that is not based on another weapon?

 
There is not, no.

Hello, I created a homebrew magic item that I'd like to link to a homebrew monsters stat block. Is this possible?

Quote from the_sleepy_DM >>

Hello, I created a homebrew magic item that I'd like to link to a homebrew monsters stat block. Is this possible?

 
Please see the General Homebrew FAQ #9.

This might not be the place for this and if so, SORRY. BUT.

I'm trying to create a +1 longsword with the finesse property. Easy, right? Thought I did it. Bonus Melee Weapon Attacks and Damage Melee Weapon Attacks, plus Weapon Property: Finesse EXCEPT that when I added it to the inventory of my player's character, the TOTALLY MUNDANE DAGGER that she also has keeps improving to match the stats of the longsword. In other words, the sword should be +6 attack and +5 damage and the dagger should be +5 attack and +4 damage, but they're both either +6/+5 or +5/+4 and I can't figure it out.

Please help. What'd I do wrong?

Quote from Shadowhawkthemonk >>

This might not be the place for this and if so, SORRY. BUT.

I'm trying to create a +1 longsword with the finesse property. Easy, right? Thought I did it. Bonus Melee Weapon Attacks and Damage Melee Weapon Attacks, plus Weapon Property: Finesse EXCEPT that when I added it to the inventory of my player's character, the TOTALLY MUNDANE DAGGER that she also has keeps improving to match the stats of the longsword. In other words, the sword should be +6 attack and +5 damage and the dagger should be +5 attack and +4 damage, but they're both either +6/+5 or +5/+4 and I can't figure it out.

Please help. What'd I do wrong?

 
This is a good place to ask questions like that. To make a +1 Longsword with finesse, the easiest way is to start with a longsword, +1 as the template and add the following modifier to it:

• Modifier: Weapon Property->Subtype: Finesse

Since the weapon, +1 is in the SRD, it’s free for us to access as a template in the content creator. It’ll also let you see how it’s set up so you can replicate it in future if you need to.

Is there a way to create a subclass feature that increases a character's critical threat range like the Champion subclass for Fighter does? If so, can it be done with subclasses for other classes (i.e. a Sorcerer subclass)?

There's no way to do that mechanically. Even the Champion feature is just text. 

how to add a spell tool tip to a magic item?

Quote from Auneye357 >>

how to add a spell tool tip to a magic item?

 
What do you mean? You just do it the same way you do any spell tooltip anywhere. You can learn all about tooltips but following the link under #4 of the General Homebrew FAQ in post 1 of this thread. However, keep in mind that tooltips will not work on character sheets.

i looked at that guide before posting here. tool tips are not showing up and i don't understand why

Quote from Auneye357 >>

i looked at that guide before posting here. tool tips are not showing up and i don't understand why

 
It’s there, last link under #4 in the General FAQ:

As I said I look there before posting here. I did as it said in the FAQ. Tool tips are not showing up and I don't understand why. It doesn't matter now I figured out a work around

Quote from Auneye357 >>

As I said I look there before posting here. I did as it said in the FAQ. Tool tips are not showing up and I don't understand why. It doesn't matter now I figured out a work around

 
Where are they not showing up? On a character sheet, or somewhere else? Is it a homebrewed spell?

Was trying to add spell tool tips to a magic homebrew item. I starred at that page trying to figure out if I missed something in the discerption. I don't know what I am doing wrong.

[Tooltip Not Found] 

what am I doing wrong

As long as it’s an official spell you simply type this without the underscores: [_spell]fireball[/spell_], and you get this: fireball. Remember, the tooltip will not actually add the spell to the item.

Quote from Auneye357 >>

[Tooltip Not Found] 

what am I doing wrong

 
What spell are you trying to tooltip?

that's what i was doing though it wasn't showing up in the item discerption