Stifle Tower
Punch Bowl Re-Filler
Avery Bradley is definitely a SG in a PG's body. He won't provide the passing/distributing abilities of a prototypical PG (which shouldn't be a problem with Hayward facilitating the offense), but he will provide the great defense & decent shooting that will allow the team to follow the formula that made them successful with Exum as the starting PG...Of all the options, including standing pat, I believe that he makes the most sense (assuming the price is reasonable).
That last bit is the key. Ainge has a reputation for trying to squeeze excess value out of every trade. Celtics have no reason to move Bradley. He's a combo guard so he can play SG for them with Thomas or Smart starting at PG. A Thomas/Smart/Bradley rotation, with RJ Hunter getting some burn looks pretty good.