I don't see any reason not to participate in the AAJ, but given that the AAJ won't accept anything under Grade 4 there's probably quite a bit being done that's not covered. A Dead Tree copy eventually - first you have to figure out what to print, and for this I'd suggest a steering commitee, but NOT one affiliated with a major organisation. The Mountaineers/Mazamas, et al have their own journals, and I fail to see why they'd commit the resources/time to another - and the AAC already has their own journal (even if it's diverging from the path of the membership)
Why not form a new club? Clubs are nothing more than a group of people who decide to bond for a common purpose. The Pan-PNW Climber's Society or something or other...