I don't know if this has been brought up yet, but I suggest that you should put in some new feature for sharing between alliances
1) Share gates/slots. If you have some slots that you do not need, you can share them with other airlines that you have in your alliance. Maybe even put in a discounted buy/lease option
2) Aircraft Sharing. Say you have a Embraer E170 that has 19 available hours on it. Wouldn't it be nice if you could lease some of those hours to an airline in your alliance? Be sort of a lessor yourself!