For that batch-delete suggestion we'd probably be just as well off adding a search option to look for cards that were "only in" a specific category (add an in / not in / only in list for category searches).
Case-insensitive category names would require a schema change, so that can't happen for a quite a while, though we could certainly consider it in the future.
Case-insensitive category names would require a schema change, so that can't happen for a quite a while, though we could certainly consider it in the future.