Yes, I know that, considering that Poland is frequented by students worldwide (hell knows why though, is our university variety that good ?) it wouldn't be wise to not let everyone enjoy this idea, on another note, if I opened a restaurant with this theme (just maids and butlers stuff) I can expect this would be quite fashionable, but then holding special events wouldn't be advisable, good taste dresses for girls and suits for men workers, high quality food and drinks (not 5 stars or anything close, just good enough to enjoy the meals and stuff) could make it to be very high quality place, the ideas just pop in the head as it goes, but the lack of competition on this level would probably trigger a nice income for a longer time.
Things I would avoid no matter the case of it becoming a restaurant or a cafe:
-short skirts.
-cleavage
reason: that would probably pose some danger to the girls after work, I wouldn't like it, i'm too soft ?