I don't think so, because wasn't Graypaw a little turned off by the fact he was a kittypet? Like when Bluestar asked him to join the clan, Graypaw was like "But he's a kittypet!!"
he did, but I think it was because Rusty was trespassing on ThunderClan territory. But I think he tried to argue with Bluestar when she invited him to the clan.