Largely, the same goals are served, but the symbolism is a little different. In the US, the moment when the marriage becomes official can be during a religious service; in the Netherlands, it can't.
From what you are describing, in EU you HAVE to be married by a government official even if you are religious. That's the wrong attitude to take. To each their own, let the people choose.
From bureaucratic perspective the important part is that the state is aware of the "social contract" two people made between each other and there is a witness who witnessed the "execution" of that contract. That's all. Who that witness is, as long as they are trustworthy, shouldn't matter.
In a religious ceremony you're married in the eyes of your god, and states don't have to recognize it.
They serve a different purpose, and it makes no sense for a social contract in one community to carry weight in the other.
Not really. Most folks I know, even the ones who got married in a church, were technically already married when they signed their marriage certificate at city hall.
I won't claim to be a marriage expert, but I don't think things are all that different from the Netherlands.
I guess there are actual annulments, but I always thought of those from a religious perspective, not a legal one. I can't fathom that the requirements are the same as presumably the religious one stipulates no intercourss.