I switched to view based control so I could move the mouse to change my facing, but all it does is move the cursor around the screen. Is there something I have to press to lock the cursor so I can rotate the screen or something?

Now it's locked and I don't know how to interact with the UI.. just tell me what I do to lock/unlock the cursor..

In the controls there will be a button set up up to activate the cursor. I can't remember the default setting, I think it might be "Enter". Anyway, just press that key again

Its usually Enter. Its a good idea to remember that button so that one can also use it to click on switches, levers, ladders, and doors MUCH easier then using the "Activate Center Object" button.