RE: Minimum Power Requirement
I think he needs a picture, weight. Do you do any stunts or repeat Victory Rolls.
Maybe hang it in the air by prop thrust only. Fly inverted close to the ground, do touch and goes.
Take off from grass, how tall is it ?
What is the maximum wind speeds do you fly in ? That is not a easy answer for 99 % of us.
Give him a feel for what you have & what you want it to do.
Rich