A plugin or behavior or whatever that would allow us to define nodes, which would then be automatically connected based on criteria (attributes) such as aerial, ground and aquatic access. Any object that moves to the target note would move at a given speed; interruptable (can change course).
It could be like planets linked with other planets, moons etc.; bonus points if nodes can be attached to a moving object. Nodes would branch as well, for example external nodes would lead to the 'Gate' node, which then expand into the internal nodes within the enclosed zone (for example castle perimeter).
Allow node management in runtime (create, modify and remove).
Plugin: editor that allows creating, placing, editing and removing nodes; linking nodes and removing links; specifying the links (access level) etc.
Behavior: any object this behavior is added to would behave as a node for all purposes, also define access levels and special conditions (active/inactive depending on condition).
However, editor would be more convenient due to easy overview, just like bone movement editor. That is sweet!