1) All NPCs, at least in combat ships, should fight back when shoot and damage by a player.
2 ) Escort centurion and vultures should have the same bahavior as WTD in station sector when a player with lower than dislike standing is on same sector station or not and in 1500m range.

What do the WTDs do differently than the Centurion MkIII and Vulture MkIV NPCs?

The escorts have the troublesome issue of needing to be defenders of the convoy and themselves rather than just themselves. What you're proposing would be great - for those of us who'd like to draw off the escorts to make raping the convoy easier.

WTDs scout ahead convoy. They arrive before it at destination and fly around the station until the convoy dock. If you are hated with their faction they will attack you and flare you even if you haven't attacked them.
Happens to me each time i meet a uit or a TGP in a different faction station.