I tested your project from post 1.
The problem is that the Height of pnlAction is too small.
It has a height of 100, but the bottom of btnGo is 80 + 30 = 110 therefore out of the panel height.
Then, you can move pnlOtions on its right place and set its anchors to BOTH and it works as you expect it and no need to have any Designer Script.
You should also check Handle Resize Event on top of the Main.
When you run the program and you resize the form in the lower right corner everything moves.
Be aware to keep your layout dimensions consistently.
The form dimensions in the main code is : width = 894 height = 800
The layout Layout1 is 600 x 600 ?
The layout ActionPanel is 894 x 900 ?
The dimensions when you run the program are those in the main code.
EDIT: Updated the project according to post #12