When it comes to the ability to be able to speak ones words and opinions yes. Once again I would stress though that it is assumed that when they speak it would be in a respectfully manner. Just because Sevastian is a Duke does not mean he can talk down to and disrespect every other noble in the realm with the exception of Abbigal because they hold a lesser position then Duke. Which is what he is basically doing now. What does it prove when the supposed great and honorabl Duke starts spouting Insults to the ones who are insulting him? How does this prove him to be any better and therefore deserving more respect? Respect is something that should be earned even by a Duke. Right now Sevastain is doing precious little to earn respect. He is being as much of an ass as Bowie.
Actually, because Sevastian is a Duke, it means precisely that. If anyone comes at a duke with a tone, they should damn well expect one back. The people that Sevastian hasn't been disrespected by get plenty of respect. It's a two way street, Pike.
He has a Ducal Seat, that proves him to be 'better' by hierarchal law.
I'm not saying that Sevastian isn't being an ass, but he sure as hell is showing proper respect to the people deserving of it. Even with Abbigal disagreeing with him, he has remained polite and properly respectful IC, but that is because you haven't been overly insulting with your character and you are Sevastian's equal.
I'd like to know why you feel the need to complain about every single thing my character does IC, in an Ooc manner. Mind explaining?