1) ability to restrict/prevent unauthorized shutdown
2) ability to hire several subordinated co-managers
3) ability to assign roles to co-mangers so that they can be task-limited. (also can hire more than one person in a role)
Example 1 - If one were to hire a new-routes manager, he/she would only be able to open new routes.
Example 2 - routes-maintenance manager - price/flights adjustments for pre-existing routes only
Example 3 - fleet order specialist - orders additional airplanes upon receipt of request, subject to overall fleet order specifications as set by airline owner.
etc
4) ability of primary owner to limit/restrict all kinds of activities relating to specific aspects of play and also similarly for role positions as it pertains to that specific airline.
5) Ability to relinquish airline ownership completely should the owner wish to truly transfer control so that he/she could withdraw from further play.
6) Each airline can view/accept/advertise role positions and summarize what the airline is looking for.
7) A historical record of actions performed and who performed the action.
In other words, competition would be between team-based airlines as opposed to individually-owned airlines potentially. The proposed enhancements, restrictions, and modifications to the way shared control works currently would improve many aspects of competitive play significantly.
8) Also - optionally - enable the primary owner of the airline to designate Spectators who can view the airline from the inside (i.e., a spectator can view the routes, planes, gates, hubs, the IFSW/IFE configurations, etc, but they can't change anything. - spectators can even be the entire public, or friends, or some designated group. (Spectator mode is ideal for training/tutoring, etc.)