You mean you would like FS9 to be more like FSX ? Wouldn't be simpler to just use FSX, which has all that you are asking already, even in the default airports ?
FS9 is by no means better performing than FSX, it just draws MUCH less stuff.
If you add 5x denser Autogen, airport traffic, road traffic and maybe boats and animals traffic to FS9 (and 4x larger Landclass textures and bump/specular mapping, etc, etc), it would be probably even slower than FSX, since making it as an addon product would be way less efficent than if the sim was programmed right from the start for it.
If you really care for that things, just use FSX...
