RI should apply to airline, not flights. Please see issue discussed in the bug forum.http://www.airwaysim.com/forum/index.php/topic,41830.0.html
I am willing to help testing this.2.
further limitation on "visibility" or pax allocation in general should be CI, especially for LH. Longer the route, more it should be dependent on CI of the airline. CI is cheaper to build up for LH airline. In return, LFs of LH flight should much more heavily depend on CI.
If nothing changes, my prediction in the next MT, half the airlines will be crammed into airports with LH demand, flying DC-10, 744s etc. It is because LH profits are just incredible, almost right off the bat, starting at RI=0, CI=0.
It is ok for the LH routes to be profitable, even very profitable, at RI-100 and CI between 90 and 100.
But an automatic DC-10 flight from anywhere in the world to LHR as the very first flight with RI=0, CI=0 should lead to bankruptcy, not to incredible riches....