The timeline from which you posted quotes reports that Atta was in Florida on the morning of 9/8, in lower Manhattan on the evening of 9/8, at Boston's Logan Airport "scouting" for a major portion of the day of 9/9, rented a car in Boston on the evening of 9/9, stayed at a Boston motel on the night of 9/9, and passed through a Mass Turnpike tollbooth on the way to Maine on the afternoon of 9/10.
This story reports Atta rented the car on 9/10 (contrary to all other reports I've read). Assuming that the 9/9 car rental and stay in Boston can be documented with receipts, my guess is that someone else used Atta's credit card in New York, and it sounds as if the visit to WTC is simply a theory. (Or this entire story is hogwash).
The timeline from which you posted quotes reports that Atta was in Florida on the morning of 9/8, in lower Manhattan on the evening of 9/8, at Boston's Logan Airport "scouting" for a major portion of the day of 9/9, rented a car in Boston on the evening of 9/9, stayed at a Boston motel on the night of 9/9, and passed through a Mass Turnpike tollbooth on the way to Maine on the afternoon of 9/10. What I posted was actually from rough notes I prepared a few months ago. There were several sources, including the FBI. (The one uncertain time in my list is because I did find published references to both times, but they're only a minute apart.)
Anyway, I don't think I have anything on the earlier information that you posted. But it's probably in denydenydeny's superb timeline; that would be an excellent resource to check.