There are still bugs, but most aren't game breaking. Class imbalance has been worked on, but there will always be people complaining that they aren't balanced enough no matter what.
Game has had a lot added to it over the years, which can be found in other threads here and in the Update Notes.
As for class to play, maybe try the Bear Shaman.
If you have fun, there is even a new subscription offer that just started and will be running for a little while:
http://www.ageofconan.com/news/new_membership_offers