Actually, I use non-Microsoft products besides Macs like Solaris, Linux, and MS-DOS successors. I used to not like Macs but since they threw out their old operating system and started over on sound fundamentals, there is nothing wrong with using a Mac. (Though it does take some getting used to if you haven't before.)
There are programs for both Linux and Macintosh that allow users of those platforms to run Windows programs should they choose to.
As for avoiding spyware, the best way is to use open-source programs which provide similar services but without the spying. Unfortunately, there are not enough free and open softwares available for Windows. If you want maximum internet privacy including the ability to ban popups, effectively manage cookies, block ads, etc. go to www.mozilla.org and download Mozilla which is totally free and has no spyware functions. Stay away from "free" Windows (and some Mac) programs that claim to give you something but in reality are spying on you.
WRT your last point, I'm not sure what you mean. Even Windows XP will let you "activate" it via telephone so you don't need an internet connection.