As one who has recently been on the same learning curve you have with ITForum (mine is Psygame), you are absolutely right to resist the temptation to give in to the extremists who always give away their inexperience by trying to turn the tone of a list bad with carping.
Moderated lists are censored lists. They're worse than publishing. Subscribers need to learn to use the delete key when they're too busy, and learn not to take contributions they don't approve of as personal insults.
I know Gabi and do not consider him a paragon of experience (reasoned research, yes, but computer savvy, no).
I run an un-moderated list on electronic game design and psychological research, which must straddle two worlds. At first this was difficult, because the list attracted all kinds of jerks. I threatened to make the list private. The list threatened to turn too formal and stuffy. It has achieved (in the ten months of its existence) an uneasy balance, with some very interesting contributions. The crap has ceased. The list is not chatty, but this has allowed some serious types to remain on-list, who might otherwise have left. What made the difference was when I announced a policy that the list would remain open, that the membership would remain tolerant of abuse, and that I would personally and off-list warn any offenders (and that other members might do the same). After a formal warning from me, if the offending behavior continued, I would simply lock out the individual from submitting to the list. You can do that with your "ignores" file. I have never had to carry out the policy by actually excluding anyone. In fact, I've not had to send the official warning. Only one individual actually created a stir since I started the policy. He turned out to be 13 years old. When he announced this, the complainers felt a little foolish. I was glad I had let the situation be, and that I had attracted a 13 year old who might advise us ivory tower types concerning the real world. Most "offenders" are not aware they may be upsetting someone buy contributing to list traffic. Most complainers never contribute anything but complaints. My theory is that complain solely because they have nothing useful to contribute.
But I can safely say that the ITForum has been the best I've subscribed to. The reason: your topical approach. If I had the time to canvas for volunteers for it, I'd do the same on Psygame. Come to think of it, maybe I should ask the list for volunteers. I guess the main problem is that the "gods" in the field of game research are not as identifiable as those in the IT field. By getting people like Jonassen and Grabowski, you've done yourself and the rest of us a big favor. Too bad Gabi could not contribute a paper on his work with distributed cognition, or computers as tools. Those with the most active intellectual agendas are often too preoccupied to get with this business.