Umm, no. Refusing to vote for Republican nominees contributes nothing towards reforming a party, it just makes the party completely ignore you. Do you see the Republican party catering to Libertarians (whom we do have a lot in common with on economic issues) in order to seize that .5% of voters that cast ballots for that 3rd party? Nope. They wrote them off.
The GOP is a political party. Pretty much everyone associated with it agrees to vote for the final nominee. That's part of the deal. Your don't have a constitutional right to join the Republican party and if you don't agree to their terms, why would they even let you in the door or ever support the candidates you do approve of? This is why you'll see virtually ALL (aside from Ron Paul who is only a gadfly using the GOP label to no useful end) Republicans endorse, campaign and support Romney - and that includes Palin, Santorum, Gingrich, Cain, Perry, etc, etc, etc.
You can start your own party, join an existing 3rd party, or just not vote (or even vote for Obama if you want to speed our national decline along). Refusing to vote for Romney the chameleon is certainly fine if you feel your conscience won't allow it - but screaming, wailing, making declarations that you won't vote for the Republican nominee will only get you ignored by the party. It won't help reform the GOP because they will simply write you off.
If the party refuses to listen, your advice is???
Apparently - to toe the party line.
“...will only get you ignored by the party. It won’t help reform the GOP because they will simply write you off. “
I think what you fail to see is that they ALREADY wrote us off.