Rookie error, but if, like me, you're getting regular crashes that you've never had before, go back through every file in your game folder and look for anything related to old mods and bin in, then verify your files and try the game again.

Easier if it's a fresh install - I looked for any file older than today's date and deleted the containing folder.

Game's still a buggy mess, but this post might save another doofus like me a bit of time.

Thanks for the tip. I thought I removed everything related to mods but apparently there were few leftover files that were crashing my game as soon as I got to the main menu, now everything works fine, so far at least.