Realist, on mobile devices the search function is located below your username once you click the menu icon. On desktop there's a search icon top right next to your avatar.
RE AZ Fall Classic. This is a small family run business. I doubt the methodology is complicated. I'm guessing it's ACT + plus reputation of travel team. As for the Junior event, as of 2015, I was told by the owners that they were not turning any players away.