Your conjecture falls apart when you put Hillary into the equation. SHE will not be close in any Southern states and will lose many, if not most, Northern ones.
There is little doubt that Giuliani will win the Presidency by a large margin so the <2%ers will be irrelevant yet again.
Rudyphobes are not afraid that he will lose to Hillary. They know he would win easily. Their fear is that by doing so their power to hold the GOP hostage will be OVER.
Even if there is no viable conservative third party in 2008, it is a mistake to think that evangelicals will turn out for Giuliani. Look at the 1996 results, and remember that Dole, unlike Giuliani, was pro-life. However, it is possible that the New Yorker can win without much evangelical support.
I agree that the Democrats have little hope in the lower South, TX, and the Plains States, where Giuliani will win, though probably with lower margins than Bush had. Ditto for the Rocky Mountain states, except for NM and maybe NV and CO, where the Hispanic vote may tilt the states into the Democratic column.
However, picking up PA, NJ, DE, ME, NH, and CT would more than offset defections in the upper South and Border states. The Democratic margins in NY, VT, MA, DC, and MD are probably ironclad. I don't see much change in the Midwest, except for IA, where evangelical dissatisfaction would erase Bush's razor-thin (<1%) margin in 2004.
The bellwether states of FL and OH may be a wash. In FL, retired Yankees in south Florida may well offset disaffected evangelicals in north Florida and the Panhandle. Ditto for OH, where lost evangelical voters in southern and central Ohio may be offset by strength in the Cleveland and Akron areas, which are more Northeastern than Midwestern in outlook. The key to a Giuliani victory is CA, where Giuliani's political profile is similar to that of Schwarzenegger. However, the Republican Party will have to commit to huge media expenditures in very expensive markets to have a fighting chance in that state.
Those "2%ers" include many Libertarians and independents who are concerned about the expansion of power of the federal government. Perhaps you missed the story about the FBI abusing the Patriot Act. If Giuliani's elected, expect the War on Drugs to escalate, more federal laws under the guise of "national security," and an expansion of federal law enforcement personnel.