When I did all of the above, I was having 0.1 second delay or something on my mouse movement. It was very bad. Maybe this is what they call input lag? I don't know.
Anyway, here's how I fixed it:
I did all of the above in my first post but added/changed these:
Nvidia control panel:
*Instead of using the standard display technology, I enabled G-sync
*Turned off V-sync
*Max pre rendered frames to 1 (be sure to enable the right one... there's one similar option for VR)
*Enabled threaded optimization
*I then set iPresentInterval=0 (look in the steamcommunity site guide on how to do this)
*I set all 4 of the .ini files to read only. Rightclick the files on your computer, go to preferences. There you can tick a box so no program (or you) can make any changes to it... I don't know if this is required, but I just did it to make sure (someone else suggested this). Remember that if you're making any changes to the options in game, they will be changed for that session, but if you quit the game and go in again, it will be restored to what you had before you set the .ini files to read only. To unset them to read only, Just untick the box.
Now my gameplay experience is butter smooth and enjoyable The mouse movement is very responsive like it should be and I've not had any huge issues for many hours. The only issue I have now is that when I'm lockpicking it's super fast and I break my bobby pins super fast, but I've managed to pick all novice locks anyway (can't pick advanced locks yet). It helps to have some experience from previous Bethesda games on how to pick the locks
My frame rate isn't capped, but my frame rate is around 60-80 fps and I guess that's why everything is working. When I pick locks or use terminals, the fps shoots up to 300 or something though. But I havn't got stuck anymore. But now I just press F5 to quicksave before trying anyway.
And I guess my fix won't help everyone, but if you have a G-sync monitor with 144 hz, 2560x1440 and a GTX 970 I think this might help you. If you have a stronger graphics card than me, you will get even more frames per second and there's a higher chance the problems will appear.