I get it OP. I was raised in a household where I would have been severely punished for such behavior, and sometimes I get frustrated that I get the short end of the stick on both ends as I try to do better for my kids.
Certainly model correct responses. Good manners and nice tone really are a language skill in part. With my kids if they refuse to use the nicer response when asked, I tell them that I don't answer people who talk to me meanly and that I'll be happy to talk to them when they can be nice. And then I ignore them (well I still pay attention but I don't respond or give them attention).
With saying yuck to dinner, my oldest pulled that for a long while. I don't offer substitutes unless it's a dish that's spicy or really outside of what they're used to (in which case they have to try but I already have a back up planned). After a week or so of him being continually rude about food that I knew he liked, I started giving one warning, and then I would say "Ok, if you don't like it, then I'm taking it away." And I would put the dish in the kitchen and that was it. He rarely ate a ton at dinner anyhow since he would get lunch and 2 snacks at daycare, so I knew he could survive a hungry evening. He threw a fit, but it only happened twice. He told his younger sister the other night (who's 2.5 and getting sassy) to "Stop it or mom will throw out your food. She'll really do it!!". She took him much more seriously than she did me