Well, I just did about 40 test years. The only thing, I'd say that might need to be uh... agreed upon before it starts. There;s a period of time, where the ruler of holland is a kid, same for the heirs to the kingdom. That makes him easy to assassinate, and easy for a quick 'game over' if he's ganged up on. If I was Holland, I'd ask that the first ruler 'not' be targeted by assassinations from everyone to wipe out the entire dynasty in 2 days

. Mainly, just until he's 16.
As far as Expansion goes, Holland is set-up to form Lotharingia, easier then all of the other nations that people are playing as so far, as it already owns three of the territories. So it's not like there isn't an obvious route of expansion, the route would be expanding into Germany to obtain enough land to form The Kingdom of Lotharingia. Mainly, take Netherlands, and upper/lower Lorraine.