If Trump does not hit his magic number, then things will not be in his favor. I hear what you are saying about the Party being hurt if Trump is not the nominee. However, it will be ironic to see it destroyed by a Trump loss instead of a Trump win.
Kasich, Cruz, Ryan, Romney, Bush, Rubio or whomever doesn’t matter. The GOP overrides the people and the party implodes and the country goes to hell.
I believe Mr. Manafort will prove you wrong. ;)