I am in complete agreement with you about setting limits and boundaries and discipline. We do the world NO FAVOURS when we give in to their kids all the time, especially sons. Sometimes I feel like a real disciplinarian in contrast with other parents. I try to limit my 'nos' to things that are dangerous or disrespectful (as opposed to just unsightly or embarrassing for me - does it really make a difference to me if he dumps his porridge bowl onto his high chair tray? No, because I have to wash it anyway and he's a good eater. But if he dumps my bowl, or if I've asked him not to, well that's another matter).
Because just that morning, this had happened.