When the cursor is stuck on open hand, there is a workaround to get it working again: press space. Works well for me after streaming video causes the open hand to get stuck.

I don't know whether it will fix the was-just-left-minimized issue.

I had a couple of times when the menu options like save/open/close/etc. were grayed out and I could not save (using keyboard or anything else). So far it seems to have been just a couple of isolated incidents when my system was due for a reboot based on another app activity, but this could be a very serious issue if it comes back.