Progress has been made!!!
A lot to unpack without actually being there to see the preparation and flight. These are the items I would look at first.
1. How are you determining the center of gravity (GC) on your aircraft?
This could help.
https://www.modelairplanenews.com/balancing-biplanes/
2. What are the incidences of the wings?
https://www.modelairplanenews.com/proper-wing-incident-setting-up-your-plane-to-fly-right/
3. Do you have any offsets on the motor? (Down and right thrust is common)
https://www.airfieldmodels.com/info..._of_model_aircraft/formulas/engine_offset.htm
4. Are you using any exponential on the radio and how much throw do the control surfaces have?
5. Does a ground check reveal correct control surface deflections?
6. Full throttle is not necessarily required for takeoff. Perhaps excessive engine thrust is causing a torque roll?
Finally, air does not scale, so a model aircraft will have many different parameters vs full scale aircraft.
Typically an exact scale model, built precisely from full scale plans, will not fly well.
NM156