McCain only gained traction because he was the only plausible alternative to Bush in the GOP primaries that year. In a world where Bush doesn't run, you'll probably see more high-profile candidates run, such as Jack Kemp, Thad Cochran, Tom Ridge, George Pataki, etc.
I could see that, sure, but they would have to run a hell of a campaign to beat McCain. If Bush doesn't run, McCain is still the favorite, albeit he's more of a "things can happen and his challengers are no slouches" favorite rather than a prohibitive one. His fate in the general election, assuming he lands the nomination, probably depends on how much worsefor wear he is after surviving the GOP primaries. And given how picking a complete dipshit as his VP torpedoed him in OTL 2008, it also depends some on his running mate.
Agreed in general. But Gore/Richards brings in more women and maybe makes Texas competitive. Also, if someone gets Gore to get Clinton to campaign for him helps. Getting rid of Ralph "80,000 votes in Florida" Nader helps.
Also, McCain was distrusted by the Republican mainstream for McCain/Feingold, so someone else winning like others suggested makes sense.
It is true that Richards would bring in more women. However, given that women vote Democratic anyway and it may hurt Gore in the South (outside Richards' home state of Texas, which probably wouldn't go for Gore even if he picks one of their own as VP anyway) it may not be the boost he's looking for. It may sway Florida, which we all know would be huge, but it still may not be enough.
McCain may have been less trusted by the GOP base, but remember that he has one advantage Bush didn't - he has a ton of cred among moderates and he can work across parties. The tough part is, if McCain loses Florida, he has to make up 24 EVs to get to 270. My suggestion is Pennsylvania, worth 23, and one of the districts of Maine.