Talking in terms of technicality, 'taverns' are placeholders because in its current state a tavern is actually a umberella term for many kinds of public establishments like restaurants, pubs etc, which sell food & also alcohol. Until they serve food they can't really legitimately claim that's what they are.
Relative reference from wikipedia - '
Tavern'
To stop players folding thier murderous taverns up made purely to lure guests to a doom then eliminate reputation, in a similar way to priests they could instead build 'bars' with the specific purpose of alcohol which are then licensed by petition into Inns, this would solve a lot of problems, and smaller bars can service the fortresses's alcoholic community (entire population) to socialise without grandiose distractions.
This will definitely muck up early petitioners but will create a more stable system as outside visitors will be drawn to the inn and the system for it can be tightened up considerably so that the process of petitioning is much faster.
- Innkeepers (formally known out of history context as 'lodging manager') are a new 'profession' as a upgrade of a bar manager who runs the smaller sites, guests will negotiate to stay for different purposes with the inn keeper for a time rather than make flying visits, the longer they stay on site, the more likely they are to apply for long term and begin the process towards citizenship, a wide amount of inn beds is important for this purpose.
Inns can most definitely attract performers and adventurers of a higher caliber and troupes, as well as be more well known than local bars as forming a Inn puts out a rumor, rather than relying on the method of discovery. Unsavory types will slide amongst bars, asking for rumors, making illicit deals, recruiting or otherwise trying to cause trouble.
I have no specific tally in mind, but a bar must have atleast 35 patrons in attendance and a positive reputation to upgrade to a inn. Considering later in the game with a higher population, hopefully more side-bars wont over-populate but two inns of good reputation might become a significant landmark, a means to veto petitions over a location would be useful.