CaptPPRuNe,
Not often we see you so upset!
Q: Can a novice learn to fly a 'Heavy' from a PC-based flight sim?
Well, given that almost all new type ratings start on CBT, FMC and systems etc. then progress to fixed base I would say that you can learn alot of the basics from such programs as FS2000. Even better from such programs as Precision-744 or professional training software all available on the WWW.
To be honest, any would be pilot could fly Boeing family on MCP alone provided that such was engaged and you had a reasonable idea how it worked.
However, do I think the terrorists left this to such PC-training alone -- not a chance. They were trained to do this job in the same way they train bomb makers. If you have the money, will and disipline you can do anything.
I feel total revulsion by this and offer my heart felt condolences to those lost.