Whatever I decide to do and at what level access will be restricted to, I think that a minimal subscription will be in order to offset all the administration costs involved. Probably an initial trial period of say a month and then say £0.50 - £1.00 a month. Still not figured out how to handle the verification though. Could include a free pprune.com email address and require participants to register using real names or new pseudonyms but with, as mentioned above, qualifications in profile.
Maybe have member status and observer status to allow others directly connected. I do agree that ATCO's should be a part of it. Engineers & Technicians maybe. I remember the days when CHIRP was just pilots and ATCOS followed by engineering but I think thay have become a bit too PC with the addition of cabin crew and ground handling personel. Not that I don't think there's a place for debate for them too but you have to draw the line somewhere and this is primarily the 'Professional Pilot' Rumour Network.
Good input so far. Keep your views coming.