What are the problems with the "A song of ice and fire" series?

[Cikomyr]

I'd say that's not true; there were quite a few elements of 11th century Christianity that would be at odds with modern-day morality. By contrast, the Faith of the Seven seems quite capable of co-existing with other religions and does not condemn those who do not follow it, with more of a focus on charity, goodwill and trying to offer counsel. There seems no religious tension in Westeros. There seems to be no agressive push to, for example, evangelise the North.

Only in later books have we seen the Seven become more militant, but that change seems genuinely motivated by the ravages of war upon the kingdoms and its people.

There is a rather dismissive attitude from each Faith members toward the other's faith. (talking of the relation between Old Gods and the 7. Everybody hates the Red God, and he gives it back). With the exception of honorable and respectful characters, off course.

I'd say the attitude of the Faith of the 7 toward the Old Gods is a bit like the latest Pagan holds in early Middle-Age. You don't want to go Evangelic on their ass since you don't have the power to actually enforce that faith upon them. As long as they don't encroach on your territory, you let these primitive people to be damned.

Remember that the only person converting from the 7 to the Old Gods created something of a stirr.