A couple of more detailed questions: Can I do this raiding with a navy alone (simulating a cross between marines on board my navy ships and the vikings who both crewed the ships and went ashore to fight once they got where they needed to go)? And can I get a large initial bonus simulating the initial plunder with (or in place of) the tributary government you mentioned? And can I raid PC provinces as well, and if so, without a declaration of war proper (even though they will most likely declare war on me for it anyway)?
Also, unrelated, can air units paradrop land units?