Translation:How many women and men are standing at the stop?
No "Bus" should not even be used here "megálló" could equally be a train or a tram stop
Is it necessary to repeat 'hány twice in hungarian? In english we will often say, "how many women and men are standing...".
Also, unless the stop had a shelter I would be more likely to use "at the stop" rather than "in the stop". Whether I am inside of or outside of the stop i could still say "at the stop". Does the inessive case also translate to "at"? Or is there another case that is more specefic towards meaning at something without being in it or on it?
Like in English you can either say "hány nő és férfi" - "how many women and men" or "hány nő és hány férfi" - "how many women and how many men" if you want separate numbers, for instance.
In Hungarian you refer to waiting for a bus at the stop as megállóban. Maybe think of it as "inside the area where you can board the bus". If you say megállónál (lit. "by the stop"), it sounds like you're hanging around next to the stop and don't actually wait for the bus.
Is 'hany' always followed by a singular noun and singular verb? In English it is followed by plurals. Is this like 'sok'?
Yes, it's like sok. It's an indication on the number of people, so you go on with singular grammar.