I only discovered this yesterday, Rabagast, so I'm super happy to share the knowledge.
What you want, I think, is "Set Property".
You can specify a specific component if you wish. For example I turn FSMs on and off within my Player object, but leave things like the Mesh Component and Physics components switched on.
You can go even further and manipulate specific Inspector entries. It's super powerful.
In fact as a shortcut you can just drag objects from the Hierarchy or components from the Inspector directly into a state and playMaker will automatically suggest using Set Property.
Hope this helps!