Answers:
1) explorer.exe is averaging at 10% and as soon as I stop moving the mouse it drops to 0%.
2) explorer.exe is averaging at 7% and as soon as I stop moving the mouse it drops to 0%.
3) iexplore.exe is averaging at 40% and as soon as I stop moving the mouse it drops to 0%.
(2) is normal, (1) is borderline, and (3) seems somewhat excessive - my IE does ~20% on a relatively busy page (
www.smh.com.au).
At least it shows that your issue is not specific to explorer.exe. Any process whose window(s) is being pelted with WM_MOUSEMOVE messages will consume processor time to deal with the mouse movement in whatever way it sees fit.
What surprises me is that I cannot spot evidence of 3rd-party code or driver interference in your ETLs. Virtually all of that activity is in user-mode, and it's all expected and necessary: sending window messages, invoking window procedures, checking the owner of a particular rectangle... It's just that it all happens slower than it should, given your specs.
Obviously something improved around the time you removed RMclock because the utilisation dropped so drastically. If you're still encountering an unequivocal improvement when running in safe mode, I'd suggest a little basic safe mode troubleshooting:
Fire up MSCONFIG, choose a "diagnostic" startup, reboot... any improvement?