Safari won't close, therefore my macbook pro won't shut down... HELP!, Safari won't close, therefore my macbook pro won't shut down... HELP!

You can force quit by clicking on Safari on the menu bar, then force quit, or the apple menu and click force quit, or control click on Safari on the dock.

Try the different force quit approaches to get out of it.

This knowledge basearticle has more on force quit.

And if for some reason you can't click on it, you can press Cmd-Alt-Esc to open the Force Quit window.