I'm not 100% on this, but I think that when we're looking at load factors, we do not include cancelled flights in this metric... I notice that if your flight cancels one day then your rolling 7 day load factor decreases. That's like saying that the airplane flew around empty that day, which isn't the case.
We do have another metric called "flight completion" that allows us to measure how well we are doing at completing scheduled flights, and usually the one we look at is "controllable flight completion" (I'm not sure what controllable flight completion excludes, I think weather)
I know that there's a lot of talk of hub cities, not sure how you're going to implement this (or how it already is implemented), but I suggest that the easiest way to make this most realistic is to have free reign on your home country, and simple cabotage rules for international flights: IE you may only carry passengers destined to or from your home country.
US based carrier: ORD-YYC-YVR-LAX
The flight may have passengers embarking and disembarking at each stop, however from the passenger's perspective these are the itineraries available:
A foreign flag carrier cannot carry passengers point to point in a country.
Canadian based carrier: YYZ-ZRH-DEL-ZRH-YYZ
on the first stop in ZRH passengers may disembark only, not embark
in DEL all passengers from YYZ disembark, and only passengers destined for YYZ may embark
on the second stop in ZRH passengers may embark only, not disembark.
A foreign flag carrier cannot carry passengers to a country other than its country of registry.