Personally, I don't claim to have any insight into Bush's mind, or that of another. I have no idea what Bush wants me to believe; all I have is what the press reports concerning things, which may or may not accurately represent reality on this, as on any other, point.
As to how sophisticated terrorists are, let us not kid ourselves, many of them have received good educations, and there is no evidence that willingness to resort to violence to get your way is genetically tied to lack of intelligence.
To have eluded capture as long as the surviving terrorists have is indicative of considerable resourcefulness and cleverness at keeping out of the hands of the officials looking for them. Try not paying a couple of bills for a while and see how good you are at evading a skip tracer or a repo man, folks, and I'm sure you'll get my point pretty quickly.
Certainly they have shown considerable cleverness in the 9/11/2001 event. Some of their more recent attempts make me wonder if their best minds are gone, but more likely it represents the fact that you can't plan something like this without leaving tracks, and they're being tracked by the intelligence equivalent of superb blood-hounds.
Sophisticated:? As much, I'd say, as most of us on Yahoo Answers, and more than most of the folk I've seen produce answers here. As sharp as the top answerers here? I should think most of them are not. Again, remember, in a terrorist organization (like any other) the majority of the members are just muscle to get things done; you only need a small handful of really, really sharp people to do the planning.
Simple logic, and experience watching people.