>>pg+(OP)
Idea 2. Restrict memberships like Gmail invitations.
Give finite invitations to your YCombinator classes and alumni. Have them pass out invites to people they know. Give out more invites when you think you need them. At least this reroots the site back in the "Startup News" seed.
>>sunir+R4
I upvoted this but disagree. My first submission to Hacker News was an Ask HN[1]. Since that day I have been working hard to follow the advice I was given there. I can't express how valuable the advice was to me. Under your suggestion, that would be impossible.