I think it's kind of fun actually. I had huge problems with a succession war because I got excommunicated and had all of France marching through my lands. I quickly discovered that at that point it was better to just blow money until I killed the pretenders and then surrendered and abdicated to my heir.
The absolute most annoying thing that happens I think is that I marry my Prince grandson off before giving him lands, you know so I can arrange the marriage. His betrothal is to a Duchess. He joins that court, and lo and behold starts a war of independence. His father somehow manages to die giving the new heir the titles to Barcelona which (accurately) wasn't part of a kingdom, and so can't be kept in with high crown authority. Now he's losing his war to the HRE and I can't do a thing about it. If I lose that duchy to the HRE I'm going to be soooo pissed.
