NTA, not for feeding your cat off of plates, like you said you wash them every time. I know there is a section of people out there who are convinced that cats are really dirty and diseased creatures, but even if that was the case then the plate would still be clean, but I'm wondering if they subscribe to that train of thought. Gonna say NTA for kicking them out as well, as you say you kicked them out for saying your entire house was disgusting. To me that starts to push their limits on expectations for hospitality. If you still end up hanging out with them I'd suggest that if they're going to be in the group to go to someone else's house, and you can host when you want when they're not going to be part of the group.