Rosalind - 1:02 pm on Feb 6, 2013 (gmt 0)
I came across an interesting graph by Akismet, tracking the numbers of comments on blogs. They fell off a cliff for most websites in 2009, about the time Twitter and Facebook took off. I don't know how that relates to forums, but social networks are where most people are having discussions now.
I don't see anything wrong with your plan to have a blog that answers common questions. Just bear in mind that you may not get as much feedback as you expect given your traffic levels, and that people will make comments where it suits them, not necessarily where you want them to.