I agree with you, it is very difficult to achieve a perfect result for the rudder hinging. In addition to this I found the composite rudder to be way too heavy (approx 70g). I am now building an open structure balsa rudder that will be hinged in the more traditional way.

Seems like I will save about 35-40g in the tail.

My fin is slightly offset to the left as mentioned in some other posts. However, I found that this could be corrected while gluing the tailpost.