Culture questions

[unmerged(200012)]

Hi. I was playing as Mazovia (one of Poland vassals in northern Poland) soon I have conquered Baltic pagans give my old polish lands to my vassals and move my realm northern into mostly Prussian lands. Now I'm king of Lithuania my ruler is Polish catholic my wife is Norman catholic and my son born as Prussian catholic. I suppose this happen because I live in Prussian lands? Anyway I have turned religion of Prussians into catholic in no time. But I found weary difficult to change culture...
All of my vassals are my family members Polish catholics. How culture of ruling character changes the game?

 

[Aardvark Bellay]

It influences technology development/spread and revolt risk to vassals of other culture.
No more than that i think , but it can get you into trouble.

Oh wait, you might get a lesser chance of getting new vassals (of polish culture) through diplomacy as well.