That's a good list of reasons, and as with most human decisions, a series of events, attitudes, and personalities converged to lead Bush to his decision. I still don't think there is a basic mystery. I hate to say this, but read Pages 253 to 274 of Plan of Attack. That was my best effort from all kinds of sources, notes, documents, calendars, and interviews with the key players, including Bush. I don't think there was a single moment when he made the decision, but there was an evolution, and it's in those 21 pages. Needless to say, much went before that, but I think that period from Christmas 2002 to Jan. 13, 2003, was critical.
Whether it was the making of the decision or the crystallizing of it, most of the answers to your questions are there. Some day we may learn more, but I haven't seen anything that adds to or changes that record.