Oooo You got me all excited since I'm currently working a bit in Enterprise Content Management... but in the argument of cost vs. value for a social forum, I think the steps you laid out should be plenty, so I won't get into crazier ideas.
Forum member adoption is crucial though, and as you've stated, finding the balance of encouraging and explaining the importance of something Vs. forcing it, being obnoxious and losing support, is a far more tricky thing than it seems on the surface.
I'll be sure to tag!