Re: Writing a story for everyone with a GLBT protagonist
The reason the games you mentioned relate to everyone is because they give you the choice, to decide for yourself. Homosexuals wouldn't be able to relate to a game with only heterosexual decisions, so the designers give them a choice to choose either sex.
By making your character a homosexual, you are inherently cutting heterosexuals off, making it so they cannot relate to the game.
There's ways designers make the character the player. I.e. In a lot of games the main character never talks, so it doesn't say or think anything that disagrees with the player. At the beginning you are allowed to name yourself, so that you are addressed as your name. You are allowed to customize your character, to give yourself an identity. You can choose your evil/nice pathways in quests, side with different people, make different decisions that make you your own person.
Having both the goal of relating to a character, and the goal of having a homosexual character's sexuality is in contradiction with itself.