I currently fly a Pitts Python and have a Goldburg Ultimate that I don't fly much anymore.....trim on a bipe is just like any other airplane...I trim for thumbs off, straight and level flight at 1/2 throttle.......CG on any airplane is best checked in flight doing the 45 deg upline full throttle thumb off the elevator trick
What is different on a bipe is the drag....all the bracing for the top wing, and probably alot more leading edge than a mono wing....sounds like you got a little slow.....
If your having tail wag issues what servo are you running on the rudder?
Nice save by the way