How do people here feel about someone asking questions about local customs in their own city or country. I mean what if I ask a question about a custom in my own city that I am genuinely curious about and it's a question that has nothing to do with my personal travels. Though it could be useful to other people who wish to travel to my city or country? I frequently see questions in the HNQ sidebar about a custom in my country that I am curious to know the answer to.
I think this is fine as long as it is, as you note, truly likely to be of interest to others who will travel to your city or country as a short-term visitor.
Questions about local that are generally only applicable to locals/long-term residents will generally be off-topic, though they might be salvageable if enough explanation is given to explain their relevance to travel.
In short, this is travel.stackexchange, not worldcultures.stackexchange, and there should be a reasonable relationship to travel. If you've got one, ask away!