Way too many sharks. I was told only one per aquarium. Plus the black sharks get really big. The bala will get really big too, and really needs a bigger aquarium and they like to school. So I would keep just one red tailed shark or rainbow shark and get read of the rest of the sharks. What type of plecos are they? Cause if they are commons, then you will need to rehome them also. And I don't think you should have the severums either. I think they would have to be on their own. So rehome them too. I think you are fine other wise.
im not overly worried about aggressivness and the sevrums and fine wit the sharks,, im just wondering a basic question,, when they all grow,, am i going to be overcrowded a lot,, a little,, soso,, not at all,, like what"?