This was the first combat spell I have ever cast (Cleric), and I fell in love instantly with DnD when i Crit the mothaf*****

nothing like the enemy cleric casts this at lvl1 character....

one of my players one-shotted an orc by groping it with this spell

This is too overpowered!

What kind of range is meant by “touch”? Is the standard 5 feet rule in effect?

Quote from MacFewncik >>

What kind of range is meant by “touch”? Is the standard 5 feet rule in effect?

 Touch here means that the target is within your reach (not within reach of your melee weapon) and that you touch the target as part of the spellcasting.

Since your unarmed strikes also have a reach of 5 feet (unless you are playing something that explicitly changes that rule, of course), I would say that it is safe to infer that your spell attack roll requires you to be within 5 feet of your target (and to hit the target's Armor Class with your attack roll, if the spell requires an attack roll). Most DMs will let you use a spell focus that you are holding to deliver a touch spell, but none of them have extended reaches anyway.

You cannot generally combine a spell attack with a melee attack, by say like trying to argue that the emblem you put on your shield is delivering your spell attack, so you might as well bash them with the shield at the same time. Nope, you can't do stuff like that unless it's in the spell description (like Green Flame Blade as an example that breaks several of these guidelines because it says it does in the spell description). The reason for this is probably that you are focusing your effort (i.e., action) in the casting and delivery of the spell. You aren't using two actions, which is what it should take to cast and deliver the spell and to deliver another attack. You would swing your shield differently, in the context of that offensive shield example. 

Quote from Thewolfhunter >>

This is too overpowered!

 It might look that way when taken in the context of how much an at-level spell slot heals. But, as they say in Star Trek: Wrath of Khan, it has always been easier to destroy than to create. Or in this instance, to injure than to heal. Better to compare damaging spells to damaging spells, and a first level spell slot typically does three dice of damage. To restrict Inflict Wounds to the amount that Cure Wounds can heal would actually nerf Inflict Wounds. 

And anything can kill a 1st level character.  Alack and alas. 

Death Domain clerics can twin this spell. Pretty neat.

Trickery Domain clerics can safely dispense this attack through their illusory duplicates (there by avoiding their vulnerability in melee range). Useful.

War Clerics can use their "Channel Divinity" to add +10 to their attack roll...meaning they will almost always hit when they wish to.

...and they can up-cast "Inflict Wounds" to absurd levels of damage.

In all fairness, and with respect to other domains...the War Cleric is the king of "Inflicting Wounds".

Quote from Tony1Adobe >>

Death Domain clerics can twin this spell. Pretty neat.

Trickery Domain clerics can safely dispense this attack through their illusory duplicates (there by avoiding their vulnerability in melee range). Useful.

War Clerics can use their "Channel Divinity" to add +10 to their attack roll...meaning they will almost always hit when they wish to.

...and they can up-cast "Inflict Wounds" to absurd levels of damage.

In all fairness, and with respect to other domains...the War Cleric is the king of "Inflicting Wounds".

 What do you mean by that you can twin this spell?

Grave domain clerics can use their Channel Divinity: Path To the Grave to curse one creature you can see within 30 ft. of you until the end of your next turn. The next time you or an ally of yours hits the cursed creature with an attack, the creature has vulnerability to all of that attack’s damage, and then the curse ends. It doubles the damage for one time. And this at 2nd level - 6d10 (!).

Ooooooh, up to 30 damage from a level 1 spell?

That settles it, I'm making a cleric XD

The first time I ever cast Inflict Wounds as my anxious character Maxi, I scored a critical and totally melted that bandit... he hasn't been so anxious since then, and the rest of the party would warn our future enemies that he "melts people!!!"

Quickly became my favorite spell and always will be.

How do I unlock this for use in game?

I love this spell. Healer my a$$.

Quote from Nasirruddeen >>

I love this spell. Healer my a$$.

 5e’s Cleric is weird and fun like that.

some cult fanatic killed me with it in one shot at 2nd level. it was annoying.

now try using this spell at a higher level spell slot. at level 9, it is 11d10, aka 110 max damage.

Quote from bob1176 >>

now try using this spell at a higher level spell slot. at level 9, it is 11d10, aka 110 max damage.

 Which is quite a waste for a 9th level spell slot, really. The average damage of 11d10 is 61/62 and you are unlikely to ever see that 110.

I can hope. but whatever, It would be super funny though if you somehow rolled max damage against a hard end of session boss, instantly killing him.