I think both of your points are important, but in an ideal world, I would go in a slightly different direction, and a bit further. First, I think that marriage is actually two distinct concepts - religious and legal. Since marriage was originally defined by religion, I don't see a problem if religion retains the right of defining marriage - a union between a man and a woman.

Legally, however, gay marriage doesn't solve all the problems. Ideally, "civil unions", granting all the rights above, would be allowed between any number of mutually-consensual partners - e.g. Mormon polygamy, Hippy communes, ... This would also bring additional recognition and acceptance to these people.