Watch how a butterfly flies. But seriously, only Hub Management knows.
FWIW, IMO, posting questions and answers (this section) probably doesn't do much for you -- except as it may help to increase your traffic by people seeing your comments or questions, then going to your profile, then maybe to your Hubs from there.
Probably more better is posting comments on others' Hubs.
But, the "biggie" is Hubs that have Hub titles and subjects (keywords) that Google searchers are looking for so you get traffic from outside of HubPages. (That will also get you some more AdSense money.)
I have never participated in the forums, so I have no idea how much that helps, if at all.