TJByrum said
But I've always wondered... what sort of stuff would realistically cause a group of random strangers to suddenly decide "better team up"? Just tell me what you think.
Well, really, you don't need them to "team up"... they don't need to use the tavern/inn as just the starting place for a "Quest." Think of the series "Cheers." Just a group of guys/gals who visit the tavern for a drink, perhaps even a bite to eat, along with a room for the night. The whole point is the tavern/inn "experience" where you can go to drink, eat and gossip, whether you be stranger or regular. Perhaps even share a room for the night, if you are so inclined (please remember to black out when you do).
That's what I think. But if you want something more to happen, say something "Orient Express" in nature, have at it. Taverns/inns can be fun places to have an adventure, in and of themselves.