Damage model is in there, I will look into the flap logic and make sure that is working as designed. Engine, oh you can definitely damage it and same with wheels. There was a post on our Discord today from someone who decided to take the plane up to 31,000 ft (not a good idea), and all the engine damage that ensued (loss of a cylinder from detonation, etc). These planes are built with large safety factors, most simulation failure models are way less forgiving than the real aircraft are, we have a failure model that fails when it should, not more than it should for the effect.
Avionics switch on the SR22s doesn't work the same as other aircraft, it only controls the Avionics bus which the most obvious items on it are the transponder and audio panel.
The rest of the graphical bugs are known and being worked on, along with sounds
Thanks for the report!