2. STR files are pretty much just ripped as is from the disc (they are video files, playable in one of the various programs available).
Here is a site that has a bunch of players/extractors for these files. As for PAK files, I know nothing solid to help you, as those are usually handled on a game-to-game basis (basically, I know of no universal PAK extractor).
3. You actually have to hit Shift + Prt/Print Scr/Scrn (You'll see different spellings, but it all amounts to "Print Screen"). And you do paste that in Paint and save, but you'll want to open that in a different program (like Irfanview) and resave it as a high quality PNG or JPG file (unless you want the full-sized BMP, which is like keeping your music in WAV format). Or you can use a program that will allow you to paste it and save right away as a different file format. But you may already know that, as you did only ask how to get the screen shot...
