I dont know the character for bottle, but I'm pretty sure the word is "ping." Should it be san ping pi jiu?
The character is 瓶.
Yes if your bar serves beer in bottles.
"啤酒" sounds like polish "piwo" (and it also means beer)
Does it? It is not surprising because it is half a loaned word - 啤 derived either from beer or Bier.
There could be a history of the world lesson in there for us somewhere!
三杯 means "three cups of".
should accept 给我们三瓶啤酒