Okay, let's go back to square one...
Are you using FSX with SP2?
Are you using PFE version 2.14?
Are you using the latest version of FSUIPC (4.60)?
I'm assuming you're running PFE on the same machine as FS, if not are you running the latest version of WideFS.
What other addons are you using alongside PFE?
What OS are you using and is it up to date with all security patches?
For FSX to freeze and/or CTD it has to be a serious contention issue and I would guess something which is writing data rather than reading data from FSUIPC which is what PFE does predominantly. According to the log PFE obviously does not detect anything untoward except for FS suddenly disappearing.
Please send me your latest PFE debug_monitor.log, just in case there's more info in that one than the last one you sent
Which anti virus program do you use?
Are you running any other security related programs and if so which ones?