That kind of topic can be included in a Geography quiz, but I think it squeezes in under the 'not more than a few of these' allowance. They are really about culture rather than Geography unless you word the question so that it is a geography-based question rather than one about the culture of the place. My quiz on the national symbols of Bangladesh was written for World (Asian Cultures). That said, a Geography editor could advise, given specific questions, as to their suitability. They would also be better placed than any other category's editors to advise on the best subcategory (which can always be changed if they think the final quiz fits better in a different place). It looks to me as if either Texas or USA - Names & Symbols would work. Sometimes there are several subcategories that would be possible, and the 'best' one depends on the exact orientation of your questions. The aim is to place it where future players might be likely to look for it.
Duplication of questions is never allowed. However, duplication of subject matter is another thing. You could probably write an entire quiz on whatever animal is the state flying mammal, so asking a different question about it than what has already been asked shouldn't be a problem.
(Editor in Humanities, Religion, Literature and Books For Children)
That's all, folks!