How about a kole tang instead of the butterfly. From what I understand, although they do get big, they are not open water swimmers so one would probably be fine in a 75 gal tank.
I like the other fish you have listed but I will mention a few of my favorates.
How about a bicolor blenny instead of the midas blenny?
A coral beauty instead of the flame angel..
A scooter dragonet instead of the mandrin (same issue with needing live food)
For your hermits, I would recommend against blue legs, they just look blah. I prefer zebra hermits (also called left handed), and the scarlet hermits.
I don't think you can ever go wrong with emerald crabs, they are simply amazing to watch.
Nassarius snails, great at eatting up left over food.
Also, you may want to consider not getting as many fish. Not because you would have too many, but because you mentioned that you might want to have coral later. In my experience, once you start having corals the level of interest in the fish goes way down.
So that was my opinion, maybe it will give you some more ideas, but even if it doesn't, good luck with your tank. This hobby is amazing.