Ok, now this is weird and it's safe to say I'm officially piffed off.
Decided against using memcleaner and went straight to disabling physx. Game crashed at first but then I remembered I had the options to read only because of what that thread had suggested, so I changed that yet whenever I wanted to change ANYTHING in the graphics options the game just crashed outside of Shadow, effect and render details. I deleted the options txt so the game can generate another. Same issue. I changed the service pack and removed it, uninstalled the community mod, deleted the exe and verified files, used the sacred file cleaner utility tool, reinstalled the game, disabled steam overlay (even though it didn't work anyway) and it still crashed every damn time.
I can live without physx but I'm not playing this game on low graphics (or in this case, medium) and no weather effects. Plus I kinda need vysnc for the 60 fps cap. Anyone willing to walk me through manually changing the options from the txt file?
Edit: Clean installed new drivers. Didn't help either.
Edit 2: Oh my god, I put the game on windowed mode and it worked. I can't believe the solution was so simple... Sigh. I'll keep you updated if the game crashes again without physx * Thank you for sticking with me through this
Edit 3: Nevermind. Crashes seem to be happening when I switch back to fullscreen now. I managed to change mostly everything I want... so I guess I'll live with it for now. Someone telling me how to change each option from the txt file would be appreciated still.
Edit 4: Physx is off. Game froze. I honestly don't know what else to do at this point.