4) Windows 7... trust me... from the very, very limited experience I have with Windows 8 (watched a friend load it on his laptop and went NOPE! Do. Not. Want.) and all the feedback I've seen from people, Windows 7 seems a lot better for gaming.
Unfortunately I think you are right. Aside from having a messy and awkward user interface, Windows 8 also doesn't seem to be optimized for games.
I am currently playing Sims 3 on a brand new gaming laptop (ASUS ROG G750JM with Windows 8.1) and
12GB RAM, and I still get these stupid little popup windows telling me that I have to "Close programs to prevent loss of information. Your computer is low on memory. Save your files and close these programs: Sims 3".
I have 2 other computers with Windows 7 Home Premium, and I have
never gotten this message when I play Sims 3 on them, which I have been doing for several years now.
I have searched for information about this strange phenomenon, and I found something about it
here.