how to prevent npc attacks

[jsr]

Personal recommendation is to use a different approach and add aggro via perl/lua, but if you want to stick with the current approach perhaps increasing the NPC's weapon delay will hide the problem a little

Lowering the player's faction for the duration of the event might also do the trick.

[Kayen]

Kayen: Implemented Perl MOB Quest Object SetDisableMelee(1=Disabled) - Prevents the ability to auto attack.
Kayen: Implemented Perl MOB Quest Object IsMeleeDisabled()

So you would use
$npc->SetDisableMelee(1);

NPC will do all its regular functions but it won't be able to auto attack

Kayen