I fully agree except for the last point. I would state it in these terms: "I want candidates who will defend the right to life". Period. Because that is how it is stated in the Declaration and the Constitution.
The on the gun control issue, for me at least, it isn't so much the fact that he voted for the assault weapons ban (although that is part of it, for sure) _but_ that he compromised a plank of the Republican party and passed a bill for Clinton that wouldn't have passed without his vote or the votes of the people in the Republican ranks that he took with him. And if elected, they can rightly claim that 'even Kasich voted for the assault weapons ban and the Brady bill'. And they most certainly will.
This betrayal of principles is more operative than the actual issue that he gave to Clinton. It is this type of softness that the liberals continue to use to whip the Republicans whether it is McCain and Graham who support Obama's restrictions of EIT's or the closing of Gitmo or whether it is using Martin Feldstein's and Lindsay Graham's comments agreement with nationializing the banks.
When those type of statements are made, the libs can use them in order to show that even (what they consider) "smart Republicans" (and they will even use the term 'conservatives') agree with them on these issues. And as far as elections go, that is exactly the type of moderate thinking that lose elections for the Republicans and that has been shown time and again. This type of behavior, while it might make those doing it the 'darling of the press' (until they actually run against one of theirs) but it doesn't win elections. And anything that we can do to discourage this, ie. by not supporting or voting for, or supporting more principled candidates in the primaries is the only way for us to gain back a majority and start winning elections.
FWIW I think if Kasich is the candidate he owes folks who feel as you do at least an honest explanation of why he took the positions he did, and an acknowledgment of the weakness it exposes as a matter of political strategy. It is a fair question and a good candidate should have a reasonable answer. Conservatives as a general rule value the Constitution as an enduring document (to borrow Scalia's words) and tinkering with any of its provisions should not be taken lightly. Laws of questionable constitutionally should certainly be avoided.