First I most to say that Linux MInt is a very good OS, I like it.
My old Linux was Mandriva 2007 or 2008, hade two applications started. One was a move player that hade a move going on, that I was looking on. In the sametime I hade Openoffice writer open (the move player was in the background) When I was working I did my writer transparent with help with exp ctrl+alt+ the weel on de mouse then I could do my application transparent an only see the text that I wrote down and the tools icon on Openoffice writer.
This funktion workt on all application in that Linux version. It hade with the CompizConfig settings to do, effects