I have no doubt that the GOP has changed over the last 20 years, but fact remains that the GOP is the white males party and they tend to vote for people like themselves.
I for one dont believe the GOP is ready to elect a black man as their presidential candidate. Steele was only elected as a response to Obama's election victory... an attempt to show that they are not the party of the white man... it backfired as everyone saw through the ploy and the GOP soon turned on their black "talisman".
I also have a hard time seeing how they can elect a woman, especially Bachmann. Had the female candidate been some what sane, then maybe but the 2 main female candidates are bat crazy and unelectable outside the GOP.
The religious issue is only key to the religious wingnuts of the right so the question will come down to turnout and % of the vote that are religious wingnuts.
As for Christie... he has his issues, but they so far are not as gaping as those of the other candidates. His main problem is he is far too moderate on certain policy issues, and that will doom him with the GOP in certain states. And yes his health issues are a major problem. Him standing beside a healthy Obama will bring back the Nixon-Kennedy situation.