1. Depends on what you consider fun... Personally my favorite profession so far has been doctor, but you might enjoy another profession entirely
2. Pretty much NT exclusive
3. All professions are dependent on gear. Unlike most other MMOs I have played, characters in AO depend a lot more on gear than on pure levels, the increase in skills from IPs per level does not make up for the jump in mob difficulty.
4. Any profession can PvP, but some are more easy to PvP with.. Again, it comes down to what you enjoy doing like in #1.. Some want to play the glass cannon uber killing machine NT.. others prefer being a heavily support orientated team player with a good doctor.. playing a highly offensive class such as a soldier is also an option for some..
TL;DR version: Any profession can PvP, it all comes down to what you enjoy playing.
5. Fairly easy in the major leveling spots, depending on your level of course.
Gear is a bit of doozy if you want to go for the ultimate, uberduber armor right off the bat.. But there are good options for new players on a budget as well
