I do not fully agree to your method of determining the downthrust, Gedexas
I would have started with centered control surfaces and motor (or perhaps motor 2 deg. right and down), trimmed the plane for straight and level flight at 50-75% throttle, and then cut the throttle at fast level flight. If the plane pitches nose down, increase downthrust - nose up, decrease downthrust. When the plane continue straight forward for a while before starting to loose attitude, you have the correct amount. With that done, pull vertical from straight'n level keeping throttle constant. Yaw left-> more right thrust, yaw left -> more left thrust.
For CG - with the aircraft trimmed,do a 45 degree dive on low throttle, let go controls. Dives a short distance and pulls out slow -> CG ok. Pitches nose up abruptly ->tail heavy, add nose weight. If it tucks under - nose heavy... Or with another plane than the Wilga, go inverted and aim for a little bit forward stick to keep it level.
And I would have made sure that the CG was pr. instruction/manual before starting the trust adjustment.
Mine was good straight out of the box, no weight added for CG, no thrust adjustment...
(The motor axle sits perfectly in center of the hole in the cowl
Trim settings guide: