I agree with most of what you have posted (I don't think I would caracterize 40% of the party as "extreme", but that's semantics). I have my doubts that Romney can succeed in energizing the base; but, with a world-class effort, it is not impossible. And if the Obama team comes up with more disasters like the contraception debacle, he may significantly contribute to Romney's efforts in energizing the republican base.
The %ages may vary - but either way I don’t mean extreme like it’s a bad thing. My reasons for supporting Romney over Newt and Santorum are not because I prefer Romney’s ideology. I’d take a solid conservative that could win. I just believe Santorum and Newt are fatally flawed in many ways and not good representatives on the conservative ideology for a presidential election.
I think Romney can do a world class excite the base effort. I hope he’s smart enough to know that he has to. The base is teaching him quite a lesson making him crawl over glass to get the nomination. That’ll leave him resenting or reaching out.