It sounds like someone is looking for a frightfully fun way to spend Halloween! Jamie, I love the way you think! You can certainly enjoy the season of happy haunts at
Magic Kingdom Park without attending the Boo Bash After Hours event. Magic Kingdom Park looks so great decorated for Halloween! I love the Mickey Mouse jack-o-lantern wreaths on Main Street, U.S.A.!
You are correct about
Disney Park Pass availability at Magic Kingdom Park on your dates of interest. The park is available on October 30th, but at the present time there is no availability at the park for regular park admission (or the Boo Bash) on October 31st. I strongly recommend making your reservations now for October 30th! The closer we get to the date, the more likely it is to become booked.
Jamie, you can always try to book a Disney Park Pass for Magic Kingdom Park for October 31st. I had an experience once where a park was marked as not having availability, but when I attempted to make a Park Pass reservation I was able to do so successfully! I was only making a reservation for one person, so perhaps that was my luck! Of course, Jamie, you can always make a reservation for any of the three parks! All three currently show availability for October 31st!
Happy haunting and...Hakuna Matata! Jonathan