There are little nods to the early Chuck (when one plotline is revealed, he's immediately asked if he "did to her what you did to all the others," which isn't exactly saying rape, but at least acknowledges that he isn't honorable there) but it is mostly glossed over. A very large part of why Logan is acceptable to me and Duncan isn't is that the writers never forgot how Logan acted, while they treated Duncan like a saint.

Starting with Angel eps likely influenced my impression of Cordy, but i liked her even in early Buffy.