Looks great!
Yeah, I noticed that padding behind the chin on the inside of the Supes sculpt. I think they put it there to prevent the sculpt from rubbing against the neck and potentially scratching it, but I can also see it potentially leaving a black mark on his neck also, as did with yours. Then again, if you never take the sculpt off, it probably won't be a big deal anyway. Regardless, I don't have the chin of mine pushed right against the neck.
I did the same thing with swapping the stand of Armored Bats and Supes. Supes has Armored Bats's crotch hook while Armored Bats has Supes's c-clamp. Where did you put the c-clamp around Armored Bats at? Around his actual fabric suit just above the belt or around the armor? I put mine around the suit just above his belt; the fabric seems pretty firm and doesn't have any piping on it the way Supes's suit does, so I'm thinking it should be okay.