Pretty much what Pils said, but also, it has the least amount of scenery, so load times are much quicker. It's the developers choice of airport when it comes to testing add ons.
It very well could be. Just keep an eye on things, and make a note of the crashes. I know other people have X-Life installed, and they haven't had any problems. But it's impossible to know what causes the crashes without physically being at your PC. The only solutions are to test at default airports, or vanilla X-Plane installs.
Keep us posted on what happens.