Perhaps the best way is to just respond in a matter of fact way.
For example with the first comment about "typical boy and typical girl," perhaps say one or two of the following sentences, "Actually, she also loves playing with tractors and tool sets. If I had a son, I would hope he would play with tea sets and dolls. I think it's so important children have the opportunity to be what they want to be and not be pushed into doing things adults think they SHOULD because they are boys or girls. I think it's so important that boys get a chance to be nurturing and caring and girls get a chance to be active and make things so they will be more rounded adults."
With the second scenario, try something similar, maybe like, "Oh, when I was a child, I was very active, more active even than my brother and I'm glad my daughter is so she'll be likely to remain fit, healthy and happy about her body. I'm quite concerned about so many girls being reluctant to do sport because they feel bad about how they look, so I want to encourage her to be active and healthy all I can," or even a slightly more sharp, short and sweet, "No, I just have a healthy, happy, active daughter."
Basically, it's not accusing the other parent of being "wrong," but stating what YOU feel to be the truth and why. That's less likely to be confrontational and most likely to be seen as "food for thought" rather than an insult.
However, that's not saying that other parents won't SEE your comments as an insult to them. They will firmly believe their views are right, are common sense, are natural, and you are the cranky one, trying to upset the apple cart with all your hippified, feminist claptrap about boys and girls not being all that different, not born "hard wired" to be princesses or pirates, choose the blue toy or the pink, etc. They will have invested alot in this "it's only natural for boys and girls to be different," crap, not just for their children, but perhaps in their own relationships.
So, be prepared to not be popular, but at least you'll keep your dignity and integrity. And, you never know when some of your pearls of wisdom might strike a chord, might make them think just that little bit differently about things, might lead them to do something a bit differently. It's always worth a try, and you'll keep more of your sanity than if you nod and smile as though you agree with them. Good luck!