Since the forum lists have so many pages now, it might be a good idea, if we could have a search page, that could let us search inside the already posted messages so we won´t write about things that already have been discussed.

Yep. I would like to see a search by author and content, or would this kill too much bandwidth again?

Author is easy enough. However the problem still exists with viewing multiple pages.
Credit to BigDogg for working out that removing the last 'threadid=0' in the address fixes the problem.