Coffee shops aren't usually a "scene" like a bar can be.
Bartenders are often the only adult in the room acting like one. When was the last time you saw fighting, crying, fainting, hit and runs, etc. on the regular at a Starbucks? Bars can be like this in even the nicest neighborhoods.
Have you ever worked at a bar or been a regular at one?
Too much or too little security will discourage customers from staying or coming back. The bartender is running the whole circus. It's nothing like serving coffee.
I wouldn't tip either. Just have the price include the labour. It is not hard concept. Nearly every single other industry has managed to figure it out.
Bartenders are often the only adult in the room acting like one. When was the last time you saw fighting, crying, fainting, hit and runs, etc. on the regular at a Starbucks? Bars can be like this in even the nicest neighborhoods.