You know
I'm like Oedipus now, my eyes already gouged out, and I can't bleed anymore. So I'll just mumble this again.
Mandate one new front page story every day. Allow only one type of vote: "I approve". The story with the most approval votes (i.e. the most popular story) at the end of the day makes the front page the next day. Then, flush the queue.
It ends -1 voting and all the negativity that brings with it. It mandates fresh content. Look how well the approval-voting diary function works at Kos, that steaming crappile of groupthink. Look how well it works at Fark.
Whatever.
I like the first idea. We don't really have enough articles posted to bother with the front page/section page split anymore -- probably never did, but back in the day it seemed like the way things were done. I think you're right that it's unnecessary though.
This ties in well with something else I've been thinking about doing anyway. I just wrote some code for Scoop (awaiting review for CVS) to handle "tags", as implemented on metafilter, flickr and so forth. I've been thinking about converting from a section categorization system to an open tag system here. Basically, when you posted a story, you'd tag it with one or more words loosely describing what it's about. So, this story might be "meta storyqueue rmgisafagort". Over time, people choosing the same words would build up a less restricted and more organic categorization system. I was thinking about starting by just tagging all stories with their current section -- so basically the tags start off mirroring the existing sections. But as we add new stories, the categories would expand. It would make it rather easier to do this if we just put everything on the front page. Also, then I could do something like making the top navigation bar just pull out the top five or six tags dynamically. That'd be pretty cool. :-)
About the threshold, I'm not very convinced it needs to change again. 40 or 50 is definitely too low. The balancing act is always to skim off the good stories and drop the bad ones, and I haven't seen many good stories going down lately. I could see maybe trying 70, but it's just not a big deal. I think going from 90 to 80 made a bigger difference than lowering it further would.