Interesting and useful. I had wondered how so many fics have the boys leaning against the bar when, here in the US, the bar is usually crowded with people sitting on stools. I like the pictures of the bar with a rail only - it aids the idea of going in for a quick drink. It also makes it more significant when characters settle in at a table.

A lot of bars here are restaurant/bars because the food puts them in a different licensing category. I forget the benefit - possibly it has to do with zoning preferences for places that serve alcohol as an afterthought (wink wink) rather than as the focus of their business.

Okay - re booth - one of your pics shows built in seats on the wall side of a table. So - what's that? Bench? Seat? Uncomfortable-but-lovely wooden place to sit?

Bartender is the more familiar term in my wealth of experience. Barkeep is something they say on old TV westerns, John Wayne movies, etc., short for barkeeper (much like bartender though I've never heard anyone say "bartend"). I think the guys who wrote and hoped to sell those stories liked the way it sounded when a cowboy/bad guy/hero would call out "BARK-eep!" Sort of like a barking dog with hiccups, yes?

Barman and barmaid make sense in the wizarding world, frozen as it is in 18th-century styles.