You are only shown the plan you are on, and you can't select a new plan until you're current plan has expired. This is not a bug, but how the theme works. If the listing is already featured, you won't be able to feature it again under the same circumstances, but if you have not featured it already you can upgrade to a featured listing. Also please note that whilst the demo site is fully functional, you cannot actually save data to it or edit listings.
Moderation can be set for new listings, but the option is not for edited listings, but if a user upgrades a listing and e.g. adds it as featured, then moderation is required again. Thanks.