Green Knight Games
1. are the hunting rules always active or only when an event card with that ship is drawn? (does a pirate NPC always try to attack a player or only if his event card is drawn)
The NPC ships only move when their flag is shown on an event card. The will move in the direction shown on the card unless there is a player ship that fits their hunt priority in a neighbouring sea zone; in which case they will move towards the player.
NPC ships will only 'scout' for player ship when the player moves with in the sea zone. If the scout is successful, combat begins.
5. If i as a pirate move into a sea zone containing a pirate NPC (first action/start of turn) and there i lose my pirate status (for instance using the rumor that gives clementsy and gold for resque a number of dutch nobles) will i then be attacked by the pirate NPC ship on my third action?
Only if you move in the sea zone as your third move, and the pirate NPC succeeds on his scouting role.
I don't think question 6 is covered in the rules.