A better search facility would be a great start! - the one above is $#!£ (that will test the none native English speakers!) I find using Google better!

A topic section or category is one more piece of information users need to enter when they ask a question. I wonder if they would enter it. Many people don't fully use the tag structure already available.

In my opinion having a drop down list of two values "Technical" and "Functional" is not a hard choice, I think these are the main topic categories that come up in this platform.