I really think the karma system should be abolished. I understand the idea behind it...to signify members whose contributions are worthwhile. Right. Unfortunately, that's not what it represents. Anyone that has even a modest degree of interest in contributing to this site quickly discerns the 15 year old trolls/post whores from the awesome members. Does NS really need an e-rep status symbol?
Just look at the forums....at any given time there are a dozen "+++K" threads. Mostly, they're spam related and utterly pointless. The children on this site who actually value karma, (and who haven't figured out that if you post 50 pics that you'll cuuuhrazyy mad karma) relentlessly respond, thus encouraging more and more worthless threads. It makes finding worthwhile posts and content really difficult. I think simply by doing away with karma, we'd see a big decrease in bullshit.
I also think post counts are a bad idea for similar reasons. I won't go there.
One other thought...how about limited thread creation powers? One per week in the general community threads? I'm tired of seeing the same jerk offs create obviously worthless/attention seeking threads.