RE: Sig Kadet JR first flight
For a first flight I'd recommend a lot of throw on the elevator and rudder, and an experienced pilot to do the flight. Low throws are fine for beginners if the plane is trimmed right and has no warps. But if it's way out of trim, you may need a lot of throw to correct it. (If you have dual rates, no problem, just set low rate where you think it's right and high rate a lot more.) Too little throw and a warp can get you to a bad place. The first Kadet Sr. I ever flew belonged to a guy who had bought it assembled and wanted someone to test fly it for him. It had so little rudder throw that it would barely turn, and I ended up just shutting it down and letting it settle into the weeds.
One thing I've found about both the Kadet Sr. and the Kadet LT-40 is that they need a fair amount of down elevator trim to fly hands-off.