Forming an empire

[LiftoCr4cy]

So I just conquered England and now I control about 90% of the de jure territory of the empire of Britannia, and thus I'm able to create the title, but I'm unsure whether I should do it. My main concern are the succession laws; will they be the same as in my primary title (Kingdom of Éire - elective monarchy) or will they be defaulted to gavelkind or something else? Also, I don't want my second son to take over the Kingdom of England since its succession law is gavelkind and I can't destroy the title yet, so will forming an empire prevent that?

[Azunai]

the newly formed empire copies the laws of your primary title. it won't change the laws of england and it will pass to your other son if you can't change the law in time. but if you form the empire, the brother who inherits england will still be a vassal of your primary heir.