I think the meal idea is somewhat interesting, but it could devalue cooking a little bit (not entirely, but it would play an impact). The mini game ideas have been proposed numerous times with a pretty mixed sentiment (personally I wouldn't mind some Dice games using pairs of Dice as those could also be used in general just for hoots).
I think a solid idea for Taverns would be to give each one a unique "House Brew" that they can have on tap that give you some special buff for a small period of time. These would probably have to be free so it isn't seen as an advantage for those with more currency, but if each one had a brew that gave you some various buff for say 10 minutes of game time it could encourage folks to at least pop by the Tavern for a drink from time to time. Plus stopping in for a drink is sort of part and parcel with the premise of the establishment. Seems almost like a no brainer.
I think another NPC would be wonderful to have in the Tavern, someone who can chat about "Recent Rumors" which could be a few different categories of actions that people are getting up to on the server (session based metrics) where whoever in the server leads in the category is mentioned by this NPC. Simple stuff like "I hear [Gamertag] has made [Amount of Gold] in the past [Period of Time]. All that coin must be nice, might make a good target if you're looking to lift a little something." Or even stuff like "They say [Gamertag] has been a regular scurge of the seas. They've sunk [Number of Ships] across the seas, I'd watch myself out there." You can add all sorts of random options like that based on the current session stats of the players assuming they are tracking that stuff. Lends itself to the idea of us making ourselves Legends of the Sea of Thieves if we were recognized in game. They could be cycled at random by the NPC when chatting with them. Plus, that means we have some more patrons on hand which fits the bill.
A band playing songs in the Taverns could be pretty solid. The Pirate Legend Hideout has a ghost band, why not a regular band in the regular Tavern? This could give us an excuse to open up the second floor of the Tavern potentially giving us more space to work with in there to accommodate fitting other stuff on to the Outposts. Live entertainment is always good to keep the patrons engaged.
Assuming all the above was addressed that would make for a pretty lively Tavern experience with a fair reason to at least pop in from time to time in your play session. Adding that to what we have now for perspective would give us:
- Barkeep (Sells regular Grog and a House Brew for a buff).
- Pirate Band (Giving some music and atmosphere to the place).
- Patrons (Mysterious Stranger, Larinna, and the Chatty Drunk).
Icing on the cake would be adding in some games, in my book. And we could also open up the second floor to keep it from being crowded.