How does AP mode work?

I am thinking of using a RT-AC68U or RT-AC3100 (when released) as an access point connected to a Linksys LRT214 VPN router.

I´ve never set up a wireless router as an AP before, so I have a few questions regarding the above setup:

1. Do the lan ports work in AP mode?
2. Does AiProtection work in AP mode?
3. Are both wireless and lan connections protected?