1) rd95's idea is a good one. Being able to share posts as an individual is a good thing. If we go behind a wall, users who have gained the ability to set community tags should be able to generate temporary share links for friends.
2) If you aren't logged in, the site shouldn't be blank. Instead, show only the badged content. That is what the community has vetted and feels is valuable. Make that our public face.
There are multiple ways you could tweak this to react to gaming by spammers, but that's the gist of it.