Interesting, since I haven't got to the end game of an MP game yet most of my strats are based of SP which, well...just won't work
In regards to raiding, is it generally considered "worth" it to be an annoyance? Taking a province, not defending it, jacking the tax rate, and moving on? Or is it "better" to take it, pillage the heck out of it and then move on if you do not have full scout intelligence of what the enemy will hit you with?
From the above, it seems that early expansion is worth it if you can get big enough to be scary. How about if you can only reach middling status, but in doing so you may provoke attacks?
Stupid, subjective question: how often do you find that people are betrayed by their own coalition? I would think the coalition would work to keep everyone relatively equal and take everyone else out before "resetting" the alliances? Not so?