I think of “reaping” as mostly a spam-removal mechanism and I am not sure that the site should bother with “auto-”reaping, based on number of negative votes nor anything else. Saying that I do or don’t like the content of a post, and saying that I think it should be reaped out of the database, is not the same thing. A relatively small number of reap votes should serve to establish the community consensus that the post should be removed. Spammers who target a site often use other bots, and a variety of sock-puppet accounts, to give their spam stellar ratings, hence my argument that the two objectives should not be blended. People can express their opinion, and that doesn’t mean they do or do not want the thing gone. Likewise, they should be able to say that they want the thing gone, without expressing an opinion.
“Hiding a post because of excessively negative reputation” would just clog up the display with hidden posts! Far easier is to just gang-up on the post and vote it off the island. If the post is noise, get rid of the damned thing. It’s a waste of time and programming to play games with it. Participants, for instance, observing that the negativity has fallen below their own level of tolerance, can proceed to consider the post for reaping. This would be their own decision, and a separate one, and a human one. The existing mechanisms would require no change.
Now, if you seriously want to improve the voting system, the most valuable change from my point of view would be to separate the up vs. the down vote tallies. Display it something like this: -2 (+5/-7). And then, most importantly, to make these separated tallies available to Super Search. If five people think that a post is great and seven people think it is stupid, well, five people thought the post was great, and that’s what I want the ability to search by. Any one of these three components ... positive, negative, and sum ... might be important to my search. (This also should mean that the vote tallies for a post will be visible to me whether I have cast a vote myself on it or not.)
Where a forum allows searches based on reputation, I find the facility to be very useful especially if the site only allows upvotes (as in “likes”). Not so useful if it goes both ways because then I might find myself searching for site-community politics. (And if the site maintains votes but doesn’t let you do anything with them in a search, well, they basically are just site-community politics.) Properly applied, a search-by-rep filter can be very helpful in winnowing the chaff, and I would find such a thing to be very useful here. (Reputation should not be the only search-criteria that can be acted upon: you must also provide some kind of keyword.)