I'm the King of both Ireland and Wales and Crown Authority is High. I had vassals in Andalusia, but somehow I lost them to Scotland during a succession. I thought, isn't High Crown Authority supposed to prevent titles from leaving the realm through succession? So what I realised is that the succession laws of my vassals in Andalusia was under the de jure crown laws of a Muslim ruler who held the title of Andalusia, despite them being my vassals.
I'm having similar problems in Wales now where the successions are not going how I expect them to because they're not operating under the supposed Crown Laws of my realm. I'm in the process of invading England now so I can create the Kingdom of England, but now I'm wondering what can of worms I'm opening.
Does changing succession laws simply not effect vassals at all? I'm under the impression that all my titles will go to my heir, but do I have to worry about the Kingdom of Wales (or the future Kingdom of England) going to someone else because of succession laws for those de jure kingdoms that I can't control? If I later change to elective, will only my Irish titles go to my elected heir and the rest will go to my first-born heir?
Can I only set the crown laws for my primary title, or can I set the crown laws in the rest of my realm and titles?