Those are flags you can set in your sale, regarding feedback at least. If someone has negative feedback, or lives outside of a list of countries, or has unpaid item strikes, the user won't even see your sale.

Confirmed address is a paypal policy you can also turn on, which forces the seller to use their paypal confirmed address when checking out or none at all. If someone wins and they ask you to ship elsewhere, you say no. Which sucks because the buyer might ding your DSRs (detailed seller ratings), which determine your ebay privileges, search ranking position, fees...

(Whoever decided that buyers should be exempt from negative feedback needs their fucking head examined)

Signature confirmation is an option you set with your shipper.