At this point it isn't a service I would pay for to drive traffic. There are many early adopters of AR that have left and their WP blogs are more than sufficient. If you aren't seeing the ROI, then it seems like a no brainer to cancel.
As you have observed. Active Rain is not a consumer website. The only business you can get is referral business. HOWEVER......
Due to the large scale human interaction, ActiveRain has REAL 'googlejjuice' (using AR vernacular) that can be greatly leveraged in regards to our WordPress website. You truly can not have too many feeder systems to your website(s). It would be beneficial to analyze the visitor experience when a feeder redirects a surfer to your site. Low conversion websites share one thing in common. Confusion.
I would suggest continuing a mirror presence on AR and link to Wordpress. It raises your relevancy score significantly.