I agree completely on the loosing Karma when say viewer 300 gets bent out of shape that by the time they try a link it is dead and this is usually on a post with less than 10 Karma assigned.
Even more frustrating is loosing Karma when you make a post with higher then average Karma since you know if you don't it will for sure die in less than a day. Then anyone with lower then the Karma restriction smites you just for putting a Karma restriction on the post.
My suggestion would be to not remove the ability to smite, but maybe restrict the ability to smite for anyone will less than "X" Karma. Or to go one step further would be to cap a users Karma once they reach a certain milestones, maybe in chunks of 25 or something like that. Once you hit 25 you cannot go down, then 50, then 75, etc.
I have to believe that someone with more than "X" Karma understands that if they are the 300+ viewer of a post with say a 5 Karma restriction they are more than aware that by 300+ views the post is most likely dead.
As for earning the needed Karma to view a post that can simply be obtained by contributing. Does not necessarily need to be in the password section. Post a good discussion topic, post some movies or pics, or post a few back doors or spoofs.
The Karma factor on this forum was what drove me to want to contribute more so I could see all of those fabulous posts everyone had posted.
My 10 cents