I wouldn't count the Heat out. Whiteside and Dragic is a nice little duo. Winslow and Richardson are some quality young players. Plus who wouldn't want to live in Miami all winter and have no state income tax to boot.
Never ever count out Pat Riley. I was pretty comfortable thinking the C's were the only real contenders for Hayward outside of Utah. Then I heard Miami. Not so sure now.
Riley also has an eternal hatred for the C's and Ainge. Like it is real.
Miami is a possibe destination for Hayward but id think Riley would have to pick up another allstar player to really attract Hayward. I dont think he goes to Miami with the roster they have now.
Boston is gonna be a much sexier choice for Hayward with IT, Horford and Brad Stevens coaching. But anything can happen between now and his final decision
Winslow missed most of the year. Richardson and Waiters played a little over half the year, and the Heat closed very well to finish with 41 wins. They aren't as far away from real contention as we would like them to be, which makes them a real threat for either Hayward or Griffin (the C's likely top two targets).
If they clear Bosh (or at least most of his contract - I don't recall what they agreement was), then they will have room for a max contract and will still be able to keep Waiters because his cap hold is so low (if they cut Ellington and let go all other cap holds, they would actually have room for a max, a mid-tier player, and can still keep Waiters). Now I don't think a team of Dragic, Waiters, Hayward, McRoberts, Whiteside with Winslow, Richardson, T. Johnson, and 14 (Giles?) is better than Boston would be with Hayward and Fultz (and no Bradley), but it isn't so far behind that Miami can totally be discounted either.