Heya.

Your experiences are pretty strange, I do get the physics changes as well (earrings, wolf ears and such 'jiggle' faster than they should).

On the flipside tho, I run an X34A (3440x1440@100hz), G-Sync doesn't appear to impact my FPS in the slightest and it certainly doesn't cause any problems with sound that I've noticed. I've never run with both G-Sync and V-Sync enabled tho as that's ill advised afaik? If it's any help, I typically get 80-100fps depending on the scene and that's with a rather heavy reshade setup going on as well.