As discussed here, I have implemented a minimum level of upvotes that a post needs to have on reddit, as well as a minimum ratio of upvotes to downvotes.
Right now I have those configured to require at least 5 upvotes, and more upvotes than downvotes (0.51). At first glance this already seems to be great improvement. There might be some tweaking later.
As a side note I have now switched from using the reddit RSS feed, to using the JSON feed. This was required in order to get easy access to the upvote/ratio properties. So there might be some new and interesting new bugs introduced because of that. It's a brave new world.
Needless to say, the first thing I'll do after releasing this, is plop down on the couch with a beer, and hope this doesn't crash. Fingers crossed!