I had the Microsoft Simulator software at one time, the one before 9/11, it was amazingly complex. Now with puters faster, LCD monitors bigger plus peripheral hardware like rudder pedals and yokes its actually quite easy to learn how to operate say a 737 sized aircraft. I learned to fly a Cessna 150 in less than 2 hours. Besides these terrorists only need the basic skills, it was observed at one of the schools of those involved in the 9/11 attacks that they had little interests in landing techniques. Besides many aircraft nowadays are so automated you basically just dial up a GPS waypoint and off you go.
I also wonder if there was actually any of the proposed safety hardware installed that required a password every half hour while in transit or the plane went into a holding pattern and could not be redirected or landed unles it was unlocked by ground control. I supposed it did go through but is a secure piece of information.
You may be right. He may need only to guide a plane left/right - up/down and he may be able to learn all that stuff.