This die hard Windows 7 fan is just about ready to join the Windows 10 crowd (and yes I also have Loonix installed). Windows 10 actually runs smoother on the machines I've been testing on.
“I’ve setup a couple of test machines with Windows 7 just to see what happens.”
Nothing is going to happen. I would just be careful about surfing questionable websites, work behind a firewall, and be really careful about email and any software you might install. I would not use it on public wifi or any network that you are not sure is secure. Also make sure that when you plug in a thumb drive or CD/DVD that it asks you what to do, and does not hunt down and run the first executable it can find. Whoever thought it was a good idea to put that in any OS should be taken out back and horsewhipped.