The airport is way up north for those of us who live south. The best airlines? Depends on your FF program, as all the major US-based airlines fly out of here. The airport is great on the inbound, ok on the outbound as long as you don't want to purchase liquids/use the restroom after going through security (except for WN, not sure about other airlines). If your flight is significantly delayed, the airport is not the most pleasant place to be.

As far as where to go/hang out, a lot of it depends on what you like to do. There are a few frequent-posters who also live here (Pinniped & Athena53 come to mind) who could probably point out a lot more than I could.

Anyhoo, in KCMO, the Plaza, Brookside, and Waldo are pretty cool. Not sure on the Kansas side of things, unless you provide specifics of what you want to do - I live here so I probably miss a lot

Watch out for the road work - there are two major highway projects going on that cut through southern Johnson County (although being from LA you won't encounter "real" traffic ) Here are some traffic/roadwork related links:

Scout System This covers the southern portion of the KC area.
Overland Park Traffic These are cameras operated by Overland Park. This is a fairly new feature.
KC Area Highway Closures - Kansas
KC Area Highway Closures - Missouri
(yes, I'm focused on the roads right now, it's raining and the idiots don't know how to drive )

I live & work in OP, so feel free to PM me with any questions.