With regards to new game. I have a few suggestions to add...

[L1011fan]

First and foremost would be able to do connections and do a real hub and spoke system.
Secondly, allow each carrier NO LESS than 2 focus cities (one is not enough, 3 is pushing it, but still ok) in the carriers home country where the flights DO NOT have to be routed through headquarters. I would say the focus cities should have at least one flight to headquarters (yes, I know, duh, of course, but there are some people who...mmm nevermind). Focus cities should not be allowed outside the carriers home country at least for the beginning, in my estimation.