As for the catchphrases, keep reporting them. They should change to the "uh-huh" at some point. As for the shirts, send each villager five of the shirt that you want them to wear by mail, in the same day.
Yeah, that's happened to me before as well, and as others have suggested, send them shirts in the mail. I've found that looking up their favourite style and picking a shirt from that list usually does the trick. You can find their preferred items on this link:
send them the tops and sell it at Re-tail just to be sure. lol. I find it cute though when they wear the same shirts.. I guess it depends on the patter of the shirts but its pretty adorable if you ask me.