Julie, answering #2: you have the same chances as everyone else. There are no special categories.
#1 I am told it is because people won those slots in the lottery before your application was picked, and then they already logged in and declined them. Next year, I'll grab the numbers right after the lottery runs, and store them. Others were reporting the same issue. Regardless, they will be there for the taking April 1.
Good luck tomorrow. Get onto the system before 10 AM, keep refreshing the screen, and work quickly when they become available.