In case you're still interested, I have a 7.x version lying around somewhere that I could upload. However, from my experience, v8 gives you access to just as much stuff in the editor (and more!) than early versions. I've been using the editor on and off for the past few years, and I haven't seen any limitations yet!

As far as compatibility with older computers, I can't comment there. I would imagine it would still work, although I currently don't have access to my Windows XP computer.