I'm surely not the only American reading this and being flabbergasted at the wildly low consumer prices mentioned. I had to double-check the post date to see if this was from 1990 or something.
What? I'm an American living in the EU, and 4 euros is a little under 5 dollars right now. Last I checked that's still one Costco rotisserie chicken. You should definitely be able to pick up a couple Miller High Lifes for 5 dollars as well if you don't live in like, Times Square or wherever.
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.