The layout of the desktop, start menu and task bar ('panel' in Linux-speak) of Linux Mint is similar to Windows 7 and should quickly become familiar (and favorite I hope ) and Linux can run thousands upon thousands of programs and games, both for Linux and for Windows-but it is a different operating system and will probably take a bit of time to find your way for everything you used to do on your computer.
So far I've always managed to find a compromise for the few such that I had (I can name but two such that stuck with me since 2006). I've never looked back as Linux does what I need and I can accept when some few things may not work as well on Linux-like some premium program on Windows may not have an equally premium alternative on Linux, or some gadget you own that can be updated by connecting it to your PC doesn't have an updater that runs on Linux.
I've made the switch to Linux back in 2006 so I'm biased and can't really answer your first question.
