To be honest, I think Wade is an excellent defender and could guard PG's, just not maybe for the whole regular season.
I don't think they are gonna throw a lot of money at Ray though. They can go out and get a Korver or something for much cheaper and fill other needs.
Don't they have like 2 players under contract (plus 3 unsigned draft picks)? With Wade and Bosh, that's another $30M+ easily. So there's not a lot of money left to fill out the roster. Giving Ray $10 million and leaving a few million for another 5 players is not a great idea.