Re: CTD's on GWX3,Wilhemshafen, St Naz... Have you tried starting at different dates and ports? I know that with V5, I get a CTD if I start a new career in aug/39 at Wilhemhafen. All the other ports are fine and I can dock at Willi afterwards, no problem. Just a shot in the dark.
Intersting how different peoples experiences can be in what they can run.
I've got a modest rig (dual-core 1.8ghz Athlon with 2 gigs of ram, running 32-bit XP-Pro, service-pak3), and I can get GWX3, Wilhemshafen-St. Naz, FM's interiors, M.E.P 2.1, MaGui, and the full MFM all running - along with a dozen other lesser mods.
I do need the 4GB patch to get MFM to run, so it does work on 32 bit OS's (perhaps because the Athlon is a 64-bit processor??), but since it's use is debatable on 32-bit OS's, I've removed MFM - the only mod that required it - just to be safe.
I think F.K.'s point about background apps may be more important than most might give it credit for. My XP install is only used as a game consol, and has never been on line. If you're using XP as your day-to-day OS, you may have picked up dozens of web active, always on, apps. Just about every program these days is running background updates, at the least.