I might be wrong, but I think math favors different starting indices based on the subject matter. I've seen Analysis textbooks favor 0 as the starting index. I don't think there's a clear argument for cultural transference from math.
I'm opposed to starting index from 1 because I think departure from very mainstream programming tradition should have a strong reason beyond preference, even if the de facto tradition appears equally capricious.
Debatable. It makes sense to say "the first element", regardless of mathematical connotations. We've had this kind of expression in almost every language across the world long before we invented multiplication.
Saying the "the zeroth element" is just... weird and slightly nonsensical.
They're both valid options and it's just about preference.