No. he will stay in as long as Trump is below 1237 delagates
This. As long as Trump doesn't reach 1,237 by the convention then Cruz has a chance. Why would he drop out?
Agreed.
There are fundamental policy differences between Trump and the rest of the GOP (both the Establishment and Movement Conservatives). Supporting Trump is a real compromise for them. Trump, underneath it all, isn't different from Mitt Romney on policy; the difference is that Mitt Romney was willing to pretend he was something he was not, whereas Trump is not going to be anyone other than who he is.
Honestly without his race baiting Trump would have gotten about as far as Jon Huntsman only he's even more heterodox.