An interesting reply final 3 greens. It is certainly interesting to see your take on the matter as a PPL with some experience of a heavy jet simulator.
Certainly, with experience, navigation at 320 kts or more becomes second nature. I will under normal conditions and ATC permission happily keep 310 kts at 2000 ft until the point of intersection on the ILS...it will take 6 miles to slow from 310 to 180 kts in still air for the Fokker 100. That is just experience on the type (I have 3000 jet hours and 1000 heavy turboprop hours). We can also fly visual approaches and often our circuits are no bigger than a light aircraft circuit at many busy GA fields.
You are quite right that to 'think ahead' is very important. Modern simulators are very accurate to the flight models of the real aircraft. As for your comment about roll response of the simulator that you flew, I can't comment since you don't mention what type it was. Certainly, for the Fokker 100, the roll rate would make your eyes water compared with an Archer as it is considerably faster, particularly at speed.
Going back to the terrorists' efforts on 9/11...it was clear that the aircraft impacted the WTC at speeds of about 450 kts...130kts or so beyond the barbers pole so they were clearly not bothered about profiles, speeds or any such like. I still maintain that a PPL could achieve what they did. After all, a long line up with the building, in a gentle descent would achieve what happened to the building.
Your points about alien profiles of an airliner to a PPL are very valid. After all, no-one would expect a 200 hour PPL to do a SID, airways flight, STAR and land would they? Remember how long a type rating course is! It takes at least 3 months to be let loose on an airliner, assuming you have a CPL in the first place.