So the game was running pretty smooth on my PC, minus the crashes periodically, and the lag with NPCs. Now that the game saves and some quest issues were patched, the old Oblivion/FO3 mouse lag is back. What are the fixes for NV or is it the same as the old 'fixes', that never actually helped.

do a search for a thread on mouse acceleration in the new patch. The patch forces vsync even if its off, so thats where the lag comes from. Follow the instructions in that thread and mouselag will be gone.