I don't really see how the whole marriage system encourages the online dating thing in any way... I mean, if they're going to do it then the lack of such a system isn't going to hold them back.

I don't do it, but I don't really see anything wrong with it. Pretty normal for younger kids to be curious about the opposite gender and want to be involved with them, online or off. Graal is a really social and casual game, so it's kind of obvious it'd happen.