I can answer:-

1). Use ctrl-alt-plus or ctrl-alt-minus (on the numeric keypad). This doesn't quite work the way you would expect.....

3). type ctrl-alt-esc a skulll and crossbones will come up as the mouse pointer, click on any part of the window of the program you want to kill. You might also want to go to the shell and ps -ef and use to kill to get any remaining bits that are running.

Stu.....