So vigilante stalkers can get Twisting Fear that let's you deal your reduced hidden strike damage (nonlethal) against enemy's that you have intimidated.
So with dazzling display you get hurt every one with in 30 feat as a full road action. But that is a long time it would be better to get it shorter.
That's why you dip rogue or anything ells that have sneak attack. Because then you can take this Violent Display as a feat. if you crit or use SA you can use dazzling display as a immediate action.
So the action needed is a immediate instead of a full road action.
You can do this once every turn you use sneak attack and sneak attack has more or less the same prerequisites as hidden strike so if you play your stalker well you will do them a lot.
So what type of vigilante would you make using this feat combination.