I can answer these questions for you, I've got about 1,000 hours in the real L-39.
- If you exceed the flap auto-retract speed they do retract fully, not to takeoff. This isn't a problem unless the airspeed switch has a malfunction, which is not uncommon.
- There isn't a damper on the throttle, but the acceleration of the engine is limited by the fuel control. You can move the throttle as fast as you want, and the engine will accelerate or decelerate to get to the selected power as fast as the fuel control allows it to. Part of the first flight of the day runup is to slam the thro