Thank you for the nicely compiled list, this would have been very nice a few days ago when I was pulling my hair out trying to hunt down solutions lol.
Unfortunately I have indeed tried each of these already, and results still stayed the same.
Except for disabling hardware acceleration in the blizzard launcher, which I just tried as soon as I read it and it didn't seem to do anything at all.
I'm pretty confident that there is something actually bugged with the rawMouse CVar, the way it behaves when enabled is clearly not as intended and nothing changes the behaviour--- And of course I've tested all of these solutions with it both off and on.