In the case of the hanging cross Santa, yeah, I agree, that's a bit over the top and rude. But in the case of the FSM banner? As I've tried to point out before, Pastafarianism isn't just some joke to try and rag on Christians (or even religion in general), it's a legitimate set of moral guidelines with concern to the separation of church and state and makes some very good points in terms of the educational system. Just because this religion likes to toy with goofy concepts doesn't make it any less legitimate, or reduce it to an attack.
As for remarks about the baby Jesus and whatnot... I don't know what to tell you. People have just as much of a right to say that in jest as they do to put honest thought into it. Much of the time, non-believers are going to be ridiculed by believers anyway, so there isn't really a positive case to even be made.
And of course, none of that applies to Pastafarianism. Adherents to the Church of the Flying Spaghetti Monster believe in His Noodly Appendages as their saviors, and nothing should, or will, cause them to turn away from them.