The Cub is definitely not a new pilot, small area friendly plane.
However, you should watch as many of the Bixler Build Videos as you can. They will help you with any foam build. You should also watch a few of the Master Series build videos as well.
Here's a picture of my Slow Flyer to show the servo placement and wing assembly. The servo placement is not critical, as long as you can get your CG right.
View attachment 229330
I have reinforced the power pod BBQ skewers after several "hard landings", OK nose dives and crashes!
Moving the servos back, shortens the linkage making for less flex, but means the CG is shifted back as well and must be compensated. I just arbitrarily chose the trailing edge position as a good balance. It seems to be working for me.