It can be difficult to run a RPG that is different to normal.
The idea of being a Shop Owner, Armourer, Tavern Owner or Trader doesn’t really sound interesting.
However I don’t believe it is impossible.
Warren Spector (Director of Deus Ex) has always talked about a world of mysteries in a single city block, so why not a story in a single Tavern or Village.
So here’s how I would run this Tavern adventure. Firstly the Tavern is owned by the players but they also own role in the village/town with limited resources; Blacksmith, Trader, Physician, Tavern Manager, etc.
Secondly anything that could happen in the Village/Town; it just occurs for different reasons. Arguments between locals and adventurers could start fights, the abandoned village has secrets to find and, of course, communication is vital to keep your resources onside and to do things for you so social is present.
Each week they have to send adventurers out as parties, however as they are planning I would keep a couple of timers ready and trigger events in the tavern. When the timer runs out trigger the event and run it like an encounter, anyone who chooses not to get involved keeps planning. For example the Drunk Thief makes a stupid move and causes chaos… the argument between two brothers over the Druid gets heated and weapons are drawn.
At the same time each owner can ask for the parties to keep an eye out for stuff and the Adventurers can approach and ask the Owners for something creating a fluid bustle in the tavern.
When the adventurers go out there is one test to see how far they succeed and one test to see if they take damage of any type; for damage, I would keep a random event’s generator to see what type of damage they could take and what they need to roll to avoid it.
At the same time events can occur in the week between the planning phases that could change what they do next week.
The key thing in an RPG where combat is secondary is to create points of interest within the session, things that get the players attention. Fighting can happen in a Tavern but it would take the players getting it badly wrong for it to happen.