How well the Heat does depends how great the coaches are because this team has super talent but it doesn't blend well. Take a look at the 3pt percentages of LBJ,Wade, and Bosh. Ray Allen in his prime, they are not. In transition, they have a chance to be one of the alltime best. However unless they get a great shooter (Miller just means that LBJ or Wade is on the bench) at the PG spot they will have the problem just mentioned by Eric_Suede. Any team with some serious defenders and bigtime shotblocker is going to crowd the lane. LBJ better learn to hit at least the midrange shot or the lane will look like a convention.
And to run a "showtime" transition offense, someone has to get some serious rebounds and the focus will be to keep Bosh off the boards. Who they get for a Center better rebound well even though he doesn't have to score.
I pity the coach who has to handle LBJs ego when he doesn't get the ball and averages less than 20PPG. That was fine for Pierce, Allen and KG as they had scored enough for it not to be a big deal but LBJ is in his prime and he is going to want the ball and frankly Wade is much better ball handler in the half court. If Riley doesn't coach this year, he might be forced to coach next year and he might be too old to deal with the egos. Kareem and Magic, etc were all team player at heart. It remains to be seen of LBJ. (people talk about his willingness to pass the ball but sometimes that is just an excuse when a star doesn't take over the game when he has an advantage. Pierce, etc would take over a game if they had a clear advantage and his teammates would be feeding him bigtime).