Miami does have a lot of room to play with, but with Bosh back in the fold, and I'm sure Wade soon to follow, there wont be as much.
My understanding is that Granger and McRoberts were not official, so I don't think Miami needs sign those guys (ie: it was contingent on LBJ being back and those guys knew that).
As a side note, it is funny that a player like Ariza is suddenly the hottest commodity on the market. There is about to be a bidding war out there for him. I have nothing against him, but he's about to get $15M/year for several years from someone..... Seems like a huge overpay for a #3 or #4 player....