I don't think you can improve the avast forum... it's already great.
The PCQandA forum is a really good general computer help forum, as you already mentioned. It started as the WinMag forum, moved to PC911.com for a few years, and finally ended up at PCQ&A. I have been a member since Windows 95. You are welcome there anytime, Technical. Everyone is welcomed there.
PCQandA seems to be a good 'General' forum... Can we learn anything with it? Can we improve avast forum?