So far I have Googled up and tried the following to no result:
The Quad Core .ini edit
Turning off Desktop Composition in the exe properties
Ticking the game to run in compatibility mode
Verifying the game cache via Steam
I did get the 'Turn Windows features on or off' thing about the .Net install, but since the version it was trying to mess with is part of the OS, it doesn't show in my Control Panel. Should I simply download 3.5 SP1 and install it and see if perhaps FO3 did manage to install the buggy beta version and that is the culprit? That is the last thing I can think of to do. As it is, when it freezes, even if I CAD and pull up the Task Manager, the way FO3 windows it tends to eat my mouse so I can't see it even on the desktop and have to fight with the PC to get it to close the frozen window.
PC Specs:
Intel Core i7 2600k
8GB RAM
2 Geforce GTX 460 in SLI
Windows 7 64 bit OS
Any extra suggestions, or maybe fixes I've missed (still in the process of doing some more Google/forum digging on the issue) would be greatly appreciated.