Angels will clean your tank of the cherry shrimp and the amano shrimp they will thank you for the expensive tasty treat.
As far as Angels I currently have 14 or 15 in my 90 g now I have been do this for a very long time you do have to be some what careful with this many but.
Most people for get that they are a social and schooling fish (before some one jumps all over me go to youtube or vimeo or look in books about angels in the wild they swim in schools in the wild.)
when they pair up they do get aggressive to a point they will chase any fish that comes near their spawning leaf or slate but they will not kill any tank mates, they are way to busy tending to their eggs for that to happen.
I have also had 3 spawns at once in this tank with no problems at all I removed the fry as soon as they became free swimmers so they could be raised up otherwise the would be eaten it very short order.
you could keep as many as 10 I would think as your 75 has as the samefoot print as my 90 just not as tall.
