Flipper, here is a follow up. I called the People Dept. and asked your two questions.
1. The pilot career day was the first one held and was thought to be a big success. They do plan on doing another one in the future but do not know when yet.
2. If not successful at the interview, you may reapply one year later.

note: I have flown with several pilots that were hired on their 2nd and even third attempts. If someone keeps coming back and is not discouraged, he is definitely worth another look. Hope this info. was helpful and best wishes on your career.