Participation, or lack thereof, is exactly what is at the heart of the matter. Steve's participation is derivative not contributive. His post on this thread was a single exemplar that lead to my... diatribe, as you say. What I hear from you is that you are fine with his behavior because of his willingness to have his written content reposted on this site - reciprocity.

May I suggest that instead of having Steve insert purely promotion links to his blog in OKCTalk threads, that you offer him an advertisement banner. The admitted function of his posts are for self promotion. In this way, Steve doesn't have to participate on the forum and run the risk of his comments being construed as the official position of a public-facing company, or running afoul of any ethical conflicts of interest. A clearer distinction between the cross promotion of OKCCentral/OKCTalk, and personal non-commercial discussion in threads would avoid this type of issue arising in the future.