I would think the Dolphin is too lightly built for the 60. A colleague has a 46 in it and it flies nicely for a second airplane. The 55ax should be more than sufficient. This airplane has a reputation for being too lightly built

With regards to the exit holes for the pushrods, insert the pushrods into preinstalled pushrod guides till they encounter the covering. Then gently push till you can see where the slot in the covering is to be cut. Cut the opening from outside for better finish. This is PVC type covering, you can easily shrink it witha a hair-drier, dont use a heatgun or iron, you will burn it

Ameyam