1. Yes, a damaged Fighter that receives a second damage result during Fighter vs Fighter combat is destroyed.
Rule 10.1 should read: Damaged: flip Aircraft to Damaged side. If already Damaged is now Destroyed.
2. "Can damaged escorts that are engaged with undamaged interceptors disengage?"
If you mean can damaged Escorts withdraw (move down to the Escort Section) after a round of Air Combat, no they can not.
Just to make sure we are on the same rule, Rule 9.1.10:
pg 24
"After all first round Air Combat is resolved you must decide for each nonengaged Escort whether to continue to attack the Interceptors or to withdraw from combat."
pg 25
"For Escorts that continue with Air Combat return to Rule 9.1.6 Position Escort Fighters and follow all Fighter vs. Fighter Air Combat steps again from that point to resolve the second round. Leader and Wingman combinations are not required to remain paired."
So if your damaged Escort is still engaged with an Interceptor it cannot withdraw from combat (move down to the Escort Section), however when you repeat the steps starting with 9.1.6 you might have an opportunity to re-position your fighters so the damaged Escort is in less danger (make them a Wingman).
The intent of going back to 9.1.6 is to abstractly represent that during a swirling aerial melee fighters only have a few seconds to get a shot off on a target, then they become separated and look for other targets.
Hope that helps. -Tony
