The first issue is how he would function as the President of the Senate, having apparently burned bridges with many of its members, of both parties. It remains to be seen whether he would whip them into shape, or be faced with a revolt that would stymie the Trump agenda.
Assuming that a Trump/Cruz coalition is the strategy, what should be the tactics? Should Cruz announce the coalition and bow out of the race now, or stay in and let the coalition be announced at the convention? I could see the latter working best if Trump and Cruz can avoid blasting each other and concentrate on blasting the GOPe. This would set the stage. This also assumes the two can get their respective supporters to cease blasting each other.
This is a very critical matter; well said on your part to call this out. I think both men could work much better together if Cruz were AG, not VP, not only because their personalities don't fit well, but also, importantly, your point above. But would Trump promising (and Cruz accepting) the AG slot also work to cow the GOPe into submission to avoid a brokered convention?
I believe without a radical conservative AG who is also a ball-buster, Trump would not be able to get a Reform agenda accomplished. So I'd really rather favor Christie or Guiliani in that role. This is a dilemma. Cruz isn't a ball buster; he's a pedant who pisses people off. Better for SCOTUS. But that is unlikely to convince the GOPe to beware of him teaming with Trump for 2016.