1) It would be fun to try this on only a subset of articles posted, so we could get real A/B testing on how well it works. The same issues get posted under multiple submissions, so we could see if the quantity and quality of comments is improved by pending, independent of the topics.
2) "showpending" to allow <1000 karma people to view the pending comments, much like "showdead" today.
3) These's now a huge incentive to farm a few 1001 karma point alt accounts. You can do that with a few submissions.
I wouldn't turn on a showpending, though. If you can't get a few users to endorse you, it probably wasn't worth saying.
I suspect anything remotely substantial will get the endorsements it needs. The userbase here is more diverse than is readily apparent.