if you call everyone dude and a transfem person gets mad about it, don't get defensive. just say like "sorry, i won't do it again" and don't argue "actually it's gender neutral" or "i call everyone dude". even if you do, i guarantee she's heard that argument from someone who very much does not call people they see as women dude. i certainly have
same goes double for the word guy.
About as offensive as bro. Yes, i'm aware that it's often not even used to adress somebody directly, idgaf, just don't.