Special traders would be cool but imo they should be spread between castle, village and tavern nicely.
I'd like to see one or more daily quest guys in tavern
On beta we talked about the possibility to add a dueling zone outside the tavern in the future. We thought about how it would be cool if the zone was h2h dueling only, possibly with some drunk-effect haha.
The tavern cellar might be used in the future too...
Betting would be nice in the tavern. They could have a guy sitting at a table where you can create a bet or view current bets (with a title, a description and some options like "for all", "clan only", "lvl 80+ only", and some money options like a minimum gold amount or a set gold amount, and time of the bet like 5 min, 1 hr, 3 hrs, 1 day). You can then tell your friends/clannies about the bet and they can go there and bet. The easiest way to do this would be to make them "yes/no" bets. It would look kinda like this:
Xell/Drizzt Duel
(Clan Members only) (Set Gold Amount: 1000)
Drizzt and Xell are dueling without using any weapons. Do you think that Xell will win?
(Bet expiring in: 5 minutes)
[Yes] [No]
Once the bet timed out, the creator of the bet will then select if the YES or NOs are winners. Those who bet will have to got to the bet guy (or his assistant?) and collect their reward if they won.
I realize that betting on duels might be introduced in a future update... but in the meantime making a bet guy would be the easiest way to bet on various things.