Not quite sure I'm following you here...
I'm trying to get a hookshot that only hooks onto certain bricks, not everything.
There wouldn't be a point to the other events if we're going to have the OnHstuff event.
It's hard to explain, but that one event, and an output event that drags the player to the brick are the only events that we'll need. All the others are pointless.
Any brick it hits that doesn't have this event will already do nothing, but it will work for every brick that does have it.
As for the switching between if the brick is a target or not thing, this can be done using SetEventEnabled/ToggleEventEnabled on the OnHstuff event.