Hey there, just wanted to chime in that we are now working on cleaning up all of those old Reference Guide search results, thanks for bringing that to our attention.
Regarding old xtuple.org forum topics in search engine results, we're working on cleaning those up as well. Right now, clicking on an old xtuple.org forum link will redirect the user to the top level of these new forums. The user then must search again here for the topic. While these new forums have an excellent search system, it's still an extra step in the user experience and not ideal. A better solution is in the works!