First of all, I second that a thousand modded game like skyrim would need a 3000$ pic (especially with he spm 5.0) coming
For the CTD on save, I had the same issue, just set your video settings back to where you had 50-60 fps.
The CTD on save doesn't come because of graphic, it's because of a bug on a mod while saving + the incredibly over charger item sheet of the game
Here the master uber tricks :
Load a older saved game that don't crash on save . Open command console and type ;
Load back your saved game with the CTD on save open the console and write ;
Load back again your CTD on save saved games,.... Try to save ^^