General :: Possible For One Account To Run A Program The Others Don't?

1) In one of the pages about the differences between Linux and Windows it mentioned that new drivers mans updating the kernal. In windows something like this would erase everything. Can the kernal be updated without losing everything? 2) Can you have more than 1 account on mint? (ex: Owner, Billy, Guest...)2.2) ...Can the accounts have different access levels? (ex: Admin vs user)2.3) ...Is it possible for one account to run a program the others don't? (ex: Billy's account will load a video enhancer program on start up, but as I don't watch as many videos my account won't.)

3) How can I tell which themes/add ons will and will not work on my Firefox once I have switched to Mint?4) One of the games that I would like to follow me on the transition does not work in Linux but supposedly works in WINE according to the manufacturer. Would WINE or something like it be available in Mint?5) How hard is it to make your own theme in Mint? I'm very attached to a theme I have used for over a decade now and reproduce it in every computer I use. Can icons from windows be imported? About the computer:This will be a home computer in a multi-user household. It will be a brand new build starting from scratch with a few old personal files (videos, pictures, music, ect) making the leap. The computer is mostly used for internet, music/movies, light office work, art (GIMP!), and some games (most of which can run on Linux).