Re: No Bartenders, Vendors or Baristas on community lots
As far as i know barista will only spawn on cafe lot while bar will spawn bartender on restaurant, bar, lounge & nightclub if you place any of these in other type lots you have to click on the espresso machine/bar & hire a bartender or barista with your own simoleons
With food stalls they never automatically spawn workers if you place them in a lots, even if it is community lots like restaurant, cafe or bar, the only time the game will automatically spawn workers is if they are the ones find randomly spawn in different parts of the neighborhood (outside of a lot) so if you put them in a specific lot they don't work unless you click on the stall & hire a worker individually which will cost you a few simoleons but as far as i know this is how it's been ever since playing the sims 4
The same can be said for the chef station that can only work automatically in restaurant & cafeteria from university only works on dorms & student commons type lots. You can put chef station in other community lots but again you have to hire chef to have a chef actually spawn & it will cost you a few simoleons. i haven't played around much with the university cafeteria in other community lots so i can't give you much details other than tell you from learning from all these type of stall they usually only works automatically on their specific designated lots that they have been coded to automatically spawn workers when placed on that designated lot.
I think this automatic coded design for stalls/bar/espresso machine/chef station/cafeteria is what makes that specific lot spawn other sims that would act like how they suppose to, such as seeing sims eating in restaurant, or people getting coffee in cafes & so forth because it was coded into that lot to work that way now if you place those in other lot types because it isn't coded to that lot type the stall/bar espresso machine/chef station/cafeteria will not work because it isn't coded to that lot.
This is just from what i learned from in game experience & my own opinion from what i've seen in game so i could be wrong but hopefully that helped you clear some things out🙂