Steve, civil war is indeed what would happen if the coalition pulls out.
There is no way we can hand the governing of Iraq over to the Council. They are disagreeing amonst themselves, and they seem to be moving very slowly with the work they have set out to do, which may be cultural. Perhaps they are just traditionally not inclined toward hurry up, hurry up, the American way of doing things.
The Grand Ayatollah Sistani (see article above) might accept appointment as interim leader or administrator of the country, but then again, he probably wouldn't compromise his integrity. With his knowledge of the culture, he could advise on appointments. He would have real power, whether given it or not, because of the respect he commands. The problem is, he's probably smarter than Bremer which might cause trouble.
Steve, I disagree with you about imperialism as the only motive. I think the admininstration had a number of motives: Getting rid of Saddam, a convenient and hated target; the influence of the neo-cons who have a glorified vision of American's destiny as Enforcer of all things good and beautiful (probably what you mean by imperialism...LOL); the desire for a Middle East stronghold, from which the US can influence the area and from which they can protect the oil supply. I think they knew all along there were no WMDs, but that really got the populace behind the war, that and the hoked-up connection with 9-11.
O vision of radiant beauty, eh? I should post a photo of myself which would bring you to your knees (not in homage but in laughter.) Then, again, I won't. This is more fun.