we have a full write up on how to use the search feature on the site to maximum effect.

http://forum.lowyat.net/index.php?act=faq&article=2

As for your suggestion for upgrading the search function, we have that in our long term plans, but due to the complexity of creating a search feature which will be independent of the postings, it will take quite a bit of time. We also require lots of time to test it out as searching a 1.5 million post database for terms like "the" or "my" is going to bring the server down to a crawl.

but keep your fingers crossed, wkkay might be able to work some magic soon