ad "7. Story that lends itself to mainstream PR": Dabble Db used Smalltalk as initial marketing vehicle, so maybe "Story that lends itself to fringe (with fanatical users) PR" could also be a valid strategy...

maybe allow people to add a short, one-line description for each submission, so one has more more info to decide whether to check it out or not.

This could be possible with a mouseover description, simply throw the description into the "title" property of the <a> element.

e.g.

url: http://howtowriteagoodemo.com/consider.html

title: How to make a demo that people will truly consider

description: Gives good tips on the small things that keep people interested in your demo.

This would result in --

<a href="http://howtowriteagoodemo.com/consider.html" title="Gives good tips on the small things that keep people interested in your demo.">How to make a demo that people will truly consider</a>

I'm considering doing this for questions (i.e. submissions with blank urls). I think it would be a bad idea for stories.

Quick and dirty solution is to add a quick description to the end of the title