So, I'm actually fine with non-original shirts and houses. Non-original catchphrases are a slight annoyance, but what really irritates me is that they're always singing their old town tune ;-; Maybe it stops after a while, but for the time being, it's annoying.
what annoyed me is I made the mistake of getting to be friends with villagers on one of my pattern holding characters. They stopped mentioning her but occasionally they'll bring up mail from her like "it's the best letter I've ever received!" and even though they're both technically me it's kinda like "what about the tonnes of mail your good ol' mayor has sent you!