I know exactly what you mean. I used to work at a movie theater do that same shit. Trust me...that's one of easiest jobs there..besides ushering. You DON'T WANT TO DO THE CONCESSION STAND!!!!111!1!!
I had it a little worse....I worked at a hood movie theater.
Not only did I have the problems you had, I had to deal with "fighting" attitudes (well you did have the old lady) when folks didn't there way.
At 2 in the morning the last movies were letting out and this one fella wanted to hang around and go into other theaters so I said "You have to exit this way". He just LOST IT and chased me around the concession stand (it was a circle in the middle of the lobby). When he couldn't catch me (I was fast
) he said "Wait 'till you get outside motherfucker."
Another time, this white fella (he was the only white fella that worked there) named Patrick was working and I was in the theater watching a movie for free (not working). I watched about the 3 three fellas movie hop in then I saw skinny frail Patrick come in there, see the fellas and came up to their seats and said "Excuse me guys. You didn't pay for this movie and you are going to have t...." CRACK...one fellas cracked him across the jaw and they ran out of the theater.
Patrick was floored of course.
Your situation is lightweight. Tell the folks either abide the rules or GTFO and STFO. They don't seem to give you THAT much trouble...well except for old ladies....but I think you could take 'em if ya had ta.