Build fever is stoked. Power packs and some extra bits showed up today. Seems like most of the planes I'm building need to have the servos/etc installed during the build. Killed me to stop my Explorer build before I finished the tail boom. Guess what's on the bench tonight.
Thought I'd let everyone know I've refined my pattern technique and incorporated several of the ideas suggested here. Prior to posting, I'd cut out the body of and Explorer. It was okay but things didn't fit quite right once assembled. So I cut a new one. Bang on. Everything fit perfect. Using a finer pin and knife marks did the trick. So thanks for all your suggestions.
I also decided to use a large snap blade instead of a #11 X-Acto knife for all the longer cuts. Made it way easier to get the cuts nice and square. I have a tendency to tilt the X-Acto knife handle out as I hold it which gave me cuts that were off angle. With the bigger blade and larger handle, it was much easier to make nice square cuts. Still used the #11 for tight corners and small bits but the snap blade knife for everything else.