Inside Social lets you require social actions: facebook likes or twitter follows, from site visitors to access specified site content.
Now when visitors view your page, the content you chose will hidden behind a Social Gateway.
Yes, if you want to edit a gateway, go to https://www.insidesoci.al and you can edit existing gateways
Yes You can. With InsideSocial WordPress Plugin 2.0 and above you can now choose gateways on a per-post basis!