I don't think it will work in practice. Reddit and other voting platforms require a login to prevent spam voting and do people want Google to know which articles you like and don't? Reddit works because anonymity which Google will not provide.

But Reddit, along with most major sites now, is also rife with the same marketing manipulators and "influencers" the article is commenting on. Digg tried something similar before Reddit and was pretty much ruined by biased organized vote manipulation (brigading). Not that I agree with Google's "trust us plebes we know better than you" model of secrecy either. The SEO problem is the prime example of why this doesn't work also. Search engines have become a vital resource for the modern internet. We need an open, publicly funded non-profit search engine.

1. If the upvote button somehow stuck on later after navigating to the site, I probably would. I realize this would probably make Chrome even more tied to Google in a potentially slightly evil way though, but it might improve search quality drastically

2. I think Google could do it. They're pretty damn good at detecting bots on Google.com just by analyzing whether your behavior looks human or not, and they also have logic in place to detect fraudulent ad clicks. I think they could do a much better job with fake business listing detection but it's probably just not their focus. Search, on the other hand, is their lifeblood.