I think both Trump and Cruz understand your point. And I’m certain that the GOPe does. Those guys are going to be all in to defeat Trump. If they feel they can pull in Kasich or Romney they will give it a try. But the handwriting is on the wall - the GOPe is backing Cruz. The Bush endorsement is all the proof I need to convince me of that.
So yes, Trump can win on the second ballot but he is up against the combined forces of the well organize Cruz and the powerful GOPe.
No. The GOPe is faking like they back Cruz. They will never support him if it means he wins. He is a placeholder, nothing more.