I wouldn't be bothered with it if it was just that, but it has bad performance from the very start. And fiddling with options by turning everything to the bare minimum doesn't solve the issue too, I tried that.
You might be having issues with too many rnpcs for your computer to handle, try lowering the number down to half of what you initially tried and see if it makes things better. This particular game hasn't been optimized as well as others I've played here.
I would try, if I could set it any lower (below 60) and that doesn't explain why would it be freezing in the main menu before I even start to play and before the game loads/generates any rnpcs from simply hovering over different options.
If it's that slow right from the start, then it's an issue with your computer settings or hardware. Have you tried running the game right after restarting your computer to see if it's an issue with your RAM being old and leaking memory?
I could say that it was a hardware issue a year ago, but I now even have a new PC that is way better and there's still not much change. I did try restarting it, but it was of no help.