I use an external PC keyboard with a MacBook Pro. I changed its modifier key bindings so that the key order is more consistent with the Mac standard layout. Unfortunately, following a reboot, the preferences screen needs to be re-visited for the changed bindings to take effect.
I have a Mac Mini connected to a TV. Sometimes when the Mac wakes up from sleep, it doesn't fill the entire screen, which requires the Overscan display option to be toggled.