SolutionGrove has done work on forums to add user portraits. I know it could be easily integrated with the ratings package.
For searching by subject or author, is it really necessary to have advanced search? Full text indexing should work for most cases if you search for the authors name, for example, and subject is generally weighted higher than the content to pull that up first.
I believe UNED is using Oracle, I am not sure which version, but the intermedia driver package along with Search package from OpenACS 5.3 should provide most of the features. One thing we added in 5.3 version of search is weighting by date, so never items will be weighted higher.