If marriage is about sex and not love it is very important.
Because society clearly has more interest in heterosexual than homosexual sex.
Considering that the species is not at any risk from dying out due to lack of sexual reproduction, furthermore, heterosexual people already have the right to marry and allowing gays to marry isn't going to affect heterosexual marriage in the slightest, I think this point carries zero relevance to the topic of giving gay people the right to marry. I've also given logical reasons why society should give gay people the right to marry.
If the law changed so that you had to be 18 instead of 16 to get a driver's license would you say that fundamentally changed what a driver's license was?
Not seeing the relevance to the topic, except this seems like your way of labelling all the things I pointed out as being "not fundamental" changes to the concept of marriage without any justification of how they're not fundamental.
I would pose a counter-question but frankly your point of view bores me. I think the topic of "should gays be allowed to marry" would have a heck of a lot more honest a title if it was instead "why do some people not want gays to marry", because all we're arguing about is your narrow-minded concept of what marriage is about. You haven't provided any evidence for possible negative effects of allowing gays to marry, for example.
You don't ever concede any points, you just ignore them and move on to something else, or you'll make some irrelevant point or insinuation that you have absolutely no evidence for, like your idea that gay people only want to marry to screw the system for benefits which you dropped in this thread and then ignored as if it had never happened once your point had been blown out of the water.
Ask yourself why you need to harbour an attitude that advocates inequality. If you want to continue discussing this, then think about your argument: Why shouldn't gays be given the right to marry. Don't get side-tracked and start thinking about toasters, benefits etc because it simply isn't relevant (unless you can come up with a logical reason - and evidence if you're going to make another dodgy insinuation - for why it is directly relevant to the topic of legalising gay marriage).