I'm trying to limit the Player to only be able to activate Doors; I've been looking at the Werewolf Feed Perk, where "Filter Activation" is ued but cannot seem to get it working.

Either everything can be activated, or nothing can.

Does anyone have any ideas/knowledge of how to do this?

Werewolf uses variable08 as a checking mechanism. Meaning only if you're in werewolf form.