Responses

lol don't even start about how a ducal house have strong backings from other nobles, there are also times that dukes can fight a royal family specially if there's factions among the nobility. Like, you cannot just do stuff you want, nobles tend to have it hard since their every actions have consequences not just their to their whole family but factions as well, simple gestures done wrong could get you enemies
I don't understand how easily can a prince banish an individual from a ducal household. You're a duke, just below the royal family, you are evicted for crimes without proper basis. What the heck ducal household boycott the royal family. And just because of your whims and lustful desires. Come on how stupid can that prince be.