If a hit is clean and not directly targeted to injure someone then I have zero issue with it - on anyone, star or not.
The agitator role is a necessary evil of the game and when they are on "your" team no one has an issue with it, most of the time. Like how I rarely see Bruins fans getting riled about Marchand, to name but one example. All teams have "those" players.
I don't think there is a clear cut solution to the agitator. Someone, usually the team the pest is bugging, is going to end up on the losing end of the call. But occasionally we see the refs call for embellishment on the agitator when someone gives them a face wash and they hit the deck like they've been shot. Some more coincidental minors and a few well placed 10's would slow the agitating after the whistle and give those coaches a moment of pause.
I think the line is blurry.