I think my Niger and my Yellow Tang are dating

That is awesome, so are the pics.

 

Safety in numbers my friend.

 

Is it just me or does it look like in the 2nd picture the niger is smiling? Haha, thats awesome!

 

I would say they are disputing territory/dominance. Your tang will often posture with his tail toward the trigger because thats where his weapons are.

 

My maroon clown and my lion do the something I think the clown is hosting in the lions fins

 

see those white spots near its tail? Those are hooked barbs. all tangs have them

 

and they are sharp as all get out.

 

All tangs have them that's why there called surgeon fish. and yes there very sharp my blue hippo tale whipped me once and ripped my arm wide open almost needed stiches

 

That sucks.
I would suggest slowing down and give your tank time to mature before adding more.  I would also suggest researching your fish a little better.

 

I dont think that at all. And I agree I have seen Nigers in community tanks as well, just not small ones. And I think that was a leading factor in your issue.

 

Don't feel like a dumb axx, you can read all you want about any species but every fish is an individual. Just gotta keep an eye on new tank mates...which you were doing, but sometimes things don't work out. I've certainly lost a few fish that were supposed to be perfect tank mates according to the charts but one of them ended up chewed or beat to death.

Like mthomp suggested, if you doubt your tank stability at all def give it time and have patience. Stress causes strange behavior!

Why can't they all just get along? lol

 

I agree in that you should allow more time for your tank to settle in, before purchasing more fish. I'd recommend upgrading the size of tank if your really heart set on all these fish. I'd recommend a 180, but a 125 would do ya too.