I think you can change the behavior of your second issue. In System Preferences -> Mission Control if 'Displays have separate Spaces' is checked then only the o

I think you can change the behavior of your second issue. In System Preferences -> Mission Control if 'Displays have separate Spaces' is checked then only the one monitor should go fullscreen leaving the other to use normally.. I have it unchecked for a specific reason, but I remember before unchecking it that fullscreen was per monitor, and now it treats all monitors as one basically. I'm too lazy to log out and back in to make sure I'm right though :), give it a shot