Useless post :-)

While I welcome ideas to increase signal to noise and remove clutter I think the above scheme would make this place very unfriendly for newbies. They already have to endure unfriendly answers from older forum members like: the solution to your problem is known just google it; or this thread from 2007 answers your question why did you not find it yourself before posting.
But your idea of improving the forum quality / search-ability in general is a good one, and maybe people should just click the thank you button more often to make the good posts stand out in a positive way.