If your Mac is so old you can't do multitouch (like mine) you can set expose so that if you swipe the mouse to a certain corner it reveals the desktop. that's what I do :) I have a different corner swipe to reveal all open windows.

Also to use delete, hit fn+delete. at least I think that's the combo! Annnd that's about all I can add to that comment. I honestly never use iTunes for video, both iTunes and QuickTime kinda suck in that department, so just install VLC. it can play anything.