On the topic of flirting. I think you should be careful with it to not be irritating, and you should always have the option of skipping it entirely. But, I wouldn't worry about whether then protagonist is a man or a woman (and even if they are they could be gay). I'd just put in a chance to flirt with someone of both genders and then the player can make the necessary choices for you. Just keep the interaction neutral enough so that if it's a man and a man or a woman and a woman it works out, and you're golden.