Re: New user permission based on passcode
If you mean that users who register with a passcode become members of both the Registered group and another group (that is, they have additional permissions, etc.), I don't think Tiki can do this now. There is a "Request passcode to register" option, but this just opens up online registration to people with the passcode, who then become normal members of the Registered group.
If you want every new user to have the same permissions, you can just add those permissions to the Registered group. But if you want some new users to have different perms (who'd register with a passcode in your idea?), then for now you have to assign those individually, as far as I know. Implementing the idea would require coding changes in the registration procedure.
-- Gary