I always just assume people are whatever gender their character is. While some might think this is dangerous, I just can't fathom why guys would play female characters unless they were into dressing like women IRL too. But to each their own I suppose. However, when I'm playing the game, it matters more to me what's on the screen than what's behind it. Even if I know better, I still catch myself calling them he or she based on their character rather than the player.
So to all the guys playing girls in the game, you're all sissy girls behind the screen to me too. :P
That being said, I am female, but I don't think girl gamers are as rare and mythical a creature as everyone makes them out to be, so I see no reason to make a huge deal about it.
The reason I picked Miqo in FFXIV was because I liked the tomboyish Mithra emotes and spell casting and weapon stances in XI better than the Hume female ones that I had. So, needless to say I'm disappointed on that front, but now I can't imagine Chio being anything else - even though the super-girlishness of some of her animations makes me want to vomit sometimes. :|
On the relationship side of things, I find serious flirting in a MMO with the intent to do so in real life to be kind of creepy. I might have my character fawn over a handsome looking Elezen now and then, but I'm not looking to hook up with the player. Mostly on account of me being happily taken already.
Ironically enough, we did meet in FFXI. Been married for 6 years and counting now.