Hi,
I have no experience in Facebook integration, but in all cases, I think you should start by questioning the various providers on the asset store and see how indeed it is working, you might have a lot of work already ready as is, with some simple drag and drop component and prefabs to get you a long way already.
As for playmaker integration, I am not sure what would be required, would it be something like storing scores, accessing users?
bye,
Jean