Rudder - Did he use the two "guides" for the pushrod? These are essential for the correct operation of the linkage. Otherwise, yeah...the rods are gonna flex a lot. Also, he may want to brace the guides with triangles of scrap foam to make sure they don't have any flex. Just brace it on one side. I have done this on both my Cap and the Reflection. The linkages worked flawlessly on both. He may want to make sure that the rudder itself does not have any binding in it.

Ailerons - Start reading at post #55 in this thread...those linkages need to be VERY free.

HTH
-Jeff