Independent of all these hypotheticals, my sense is that Bradley's presence is less valuable vs. the Heat than vs. other teams.
First, Miami does not rely on the PG spot for offense.
Second, while Bradley can cover Wade, it is more of a stretch for him than it is to cover a PG.
Third, Miami has many non-PG outlet guys (Wade, Lebron, etc.) so having Bradley pressure the PG isn't as impactful.
And fourth, given that Bradley's value is in making other teams take too much time getting into the offense, Miami has two of the best shot-clock bailout options in the league in James and Wade. Heck, the way Lebron is playing right now he can get what is a good shot for him from anywhere on the court in about 3 seconds, in isolation.