I'm not sure it is a worthwhile endeavor to hope that new users hit 1000 karma. I think the discourse would be better served by having a wide variety of people saying something worthwhile occasionally rather than trying to say something popular more often to play a karma game.

The best idea I've heard so far is a timeout, such that even if no one endorses your comment is to let you comment again anyway after a day.

I'm still not sure what the benefit of adding endorsements is compared to using a generic upvote as the endorsement.