I think it would be a cool idea if you could sign contracts with other players that benefit both parties. Currently you can come to agreements with other players at the same base or at other bases as to future expansions of bases, or about current routes. Yet there is no way to make sure both parties fulfill the agreement. I think it would be great if you could sign a contract. These would of course could be time limited and could have a cancelation clause. These could limit the amount of seats each airline to add to any given route. Where they both agree to expand to in the future...