* let content producers sign their content and discount producers who have a lot of content on the web
* presence/absence of ads from known ad networks
* presence/absence of google analytics etc
* ratio of a page's download volume in bytes versus number of square centimeters of the viewport when rendered by a typical user
* cap the point at which higher update frequency scores you "ranking juice". real human beings doing a website for a non-commercial motive and who set a high bar on meaningfulness of their communication aren't going to update their site multiple times a month. you have to outsource the creation of thin content to achieve that, which is what we don't want.
* cap the point at which younger content ranks higher & cap the point at which older content ranks lower, for similar reasons. information that is great information today because it's topical, and no longer great information tomorrow was probably never great to begin with. and if content is great, then it will age gracefully. -- as a matter of fact you may want to downrank content that's very young for that reason. web search is about searching something that should be a permanent information store / archive sort of thing. if you're looking for something that's more like a newsfeed, discovery mechanisms other than search should be used.
i'm sure i could think of more. but one thing that strikes me about the above list is that a lot of this stuff is the exact opposite of what google is doing right now, so the shittiness of today's web is, to a large extent, engineered. i don't think it's within the nature of the web that it inevitably has to be like what it's like today.