I honestly can't see the difference. Leo is still the leader, Donnie is still the tech-head, Mikey is still the funny guy (they are all the funny guy though.), but Raph is not cool but rude. .... okay, I see it now.

I think it would be out of the realm

Honestly, my only problem was with Shredder & Krang. they didn't do much of anything in the movie. just bring back Ch'rell, and that's it.

Literally the same.