Yes and no. Usually a wrestle will go to creative about an idea he or she has other times creative will come to them giving " suggestions." ( but really its what they want you to wear) I've also heard that wrestlers pay for their gear if it's their own idea.

So really it depends on the situation.

Yes

I don't know for sure but I'd think they'd have at least a little say in what they wear.

THEY HAVE A SAY IN WHAT THEY WEAR BUT IT HAS TO GO WITH HIS GIMMICK.