For the aft trim problem, the boomtown boom is lighter, so turn the elevator servo link shorter 1 full turn, then 1/2 at a time until stationary.

You will never get the nose to stay in place for long no matter what You do. I pulled the rudder spring out of the TX and now I have full authority of where the nose is. don't have to mess with trim, anymore.

If You have the gain set properly, it WILL turn faster to the right than to the left, if You adjust the gain down to get uniformity, then you've defeated the gyros purpose. Why is it necessary to have uniformity on rudder. It isn't that noticeable in normal flying.