All your facts are correct, as usual. Cruz is not the slime in the unsubstantiated and out of context attacks and innuendo that are being spread by trolls. He is, based on overwhelming evidence, the "consistent constitutional conservative" you describe, and one of the most consistent, articulate, and energetic defenders of the Constitution in politics today.
Trump was a leading financial supporter fifteen years ago of anti-gun legislative efforts and of many other liberal positions. The sincerity of his conversion and the absence of evidence for an ideological understanding of why his new positions are correct are my biggest concerns with Trump. I also have concerns with Cruz (which have nothing to do with his integrity or conservatism, just with the risk that stopping Trump will lead to the establishment nominating someone who supports Amnesty, supports Obamacare, and supports restrictions on our Second Amendment rights - like Kasich).
This lack of conservative understanding for the issues we hold dear is why Trumps advisors will not let him debate Cruz one on one.
It would be too easy to make a mess of him.