To make your airports look better you have to put your Scenery sliders (complexity, autogen and add-on scenery) more to the right. It could however cause a drop in your frames if you put them too far. Just experiment with it, you'll find the best setting for your sim.
About the load times, does that happen with a default plane and default scenery or with add-ons? Add-ons can cause longer load times because of their size.
Crash
