That certainly is your perogative with which I won't argue. Every individual's vote is a prescious franchise and everyone should feel free and inspired to cast their vote as they see fit.
... but I promise heaps of derision and abuse on anyone who breaks ranks and goes 3rd party. I'm a loyal Republican...
This, I have a problem with this. First, if one is to respect your right to direct your vote as you see fit, then why shouldn't you respect theirs?
Second, and most importantly, I found the term "break rank" really offensive. I have been registered Republican all my life and voted accordingly. My conservative beliefs line up pretty much with the party platform. But the GOP does not own my vote, nor do I owe them my vote. The onus is on the Party to present a candidate who supports the platform and principles of that Party. If not, there is little reason to be a member of that Party at all, let alone vote for whichever candidate they may back. When that candidate neither resembles my acceptable-candidate* nor supports the majority of the party platform, they will not get my vote. It's pretty simple, really.
*An "acceptable-candidate" is not to be construed with an "ideal candidate" or a "pure candidate", but one who meets approximately 75% of my expectations.
That's a fair question, and I'm happy to answer it. What I fear more than anything (political) is the death of the two party system. IMHO, it would be nothing but disaster.
I've seen multi-party systems, and they're always horrid. Italy comes readily to mind. Hell, Slick comes to mind. He was the product of a multi-party system. 43% of the vote is less than a majority, but when you have 3 candidates grabbing for votes, it's easy to wind up with a winner that more people voted against than voted for.
So, it's not that I don't respect your RIGHT to direct your vote as you see fit. It's that I absolutely fear the demise of the two party system. No good can come of it, no good at all.