i think zoro is more of a white beard than shanks, disrespectful actions shanks would usually laugh off, whitebeard would not tolerate he will set an example of superiority by force he has such pride.
ace was attacking whitebeard without saying anything, nut those attacks stopped when they had a talk.
also the reason why sanks, luffy and zoro didn't stright away punish the bandit and bellamy is because the later started giving voice to stupid and wrong ideals.
so shanks, luffy and zoro wanted to punish them by
proving them wrong, zoro have said it afterward: "
a fight that would only live pity, is too painful to bother".
had shanks, luffy and zoro reacted with violence and beat up those guys, they won't only be punishing them once but twice, beaten to a pulp, and proven wrong at the same time.
great men don't believe in excessive violence, it's the reason why mihawk started the fight with zoro only using a pocket knife, you can even see zoro's reaction to the disparity of strength.
there's a great scene in the anime that shows how crushed bellamy looked after he heard the golden bell and saw luffy's shadow.