Guess I'm first then!
Welcome to Phandroid and also to Android in general, I'm sure you'll love both. Just to clear up the meanings for you, rooting is gaining access to the substructure of the operating sytem installed on your device, then you would flash (essentially install) a ROM (custom version of android. These range from unchanged vanilla android to ones with skins and extra/different features). Truthfully, this is something only someone comfortable with android should try, as doing so voids your warranty and you can brick your device if you make a mistake. Luckily, one of the best things about Android is that it is plenty customizeable without even needing to root your device. iOS needs to be jailbroken to do many of the same things.
One of the most noticeable differences as far as customization is concerned is that android has widgets for many apps. These let you do lots of stuff quickly right from your homescreens including watch videos, control music, get active weather updates, view a full-sized calendar, view running apps, make a note, and much more.
As you mentioned about the windows 8 theme, I'm sure there are windows 8 ROMS out there, but since you are new to the platform I would reccomend using a launcher instead. This will install a skin over the basic ice cream sandwich setup the device comes with. Benefits are that it doesn't void your warranty and it's a much simpler process, but isn't as integrated into the device as a ROM so changes will essentially just be cosmetic. Go Launcher is very nice and has tons of different themes you can use including windows 8 themes.
As far as other features go, there are apps to do pretty much anything. I'm still finding new ways to use my prime, but already use it for typing in class, taking pictures, watching movies on TVs, simulating circuits for electrical engineering classes, and as a fast way to browse the web. It's also nice having something so portable when building things like looking at DIY guides while working on my car. As an IT guy, I'm sure your employer will limit the usefullness of your prime as far as it directly applies at work, but at home you can do stuff like remote desktop access (the Prime even comes with a nice remote desktop feature for free in the My Cloud app). Good luck with yours and I'm sure you'll enjoy it!
-Relsek
(P.S. You would definitely benefit from being able to output a wifi signal from your phone, so you should look into doing that for whatever phone you use.)
