Please allow me to make several small points, and please understand that these are not criticims of your lifestyle.
I do not understand the reason for this question, DAoC explicitly forbids players from forming guilds that are "Hate Mongering." That includes anti-gay, anti-religious, anti-ethic, etc. guilds. Mythic also forbids players from harassing other players about above said matters.
How do people know you are gay in order to offend you, unless you openly talk about it. That would be making it a "Political" issue that isn't related to the game. I am not gay, but I am an atheist (and many people have referred to that as "spiritually homosexual"). I refuse to mention it in such a public forum as a game because the same segment of the population detest my beliefs and my lifestyle are the same that detest yours. I'd rather just enjoy the game. I don't care if people flame me on message boards and on UseNet, but I have many friends in-game and would rather them not create any political issues with me either. It is information that is impertinant to gameplay, so I simply allow the information to stay as it should - undisclosed.
There is a certain segment of the player base (children) that commonly refer to unpleasant things as "gay" like (one I've seen): "those mass mezz spells are SO GAY" Remember that these are children, and they have no bearing on your life. This is just a game - as you have pointed out. Besides, the same rules apply to their behavior as to the paying adults that play the game. Report them. Mythic doesn't tolerate it, nor should you, or I or anyone. I simply ask them not to speak like that around me - in game or otherwise, because it is stupid and offensive. If they start a major confrontation over it and begin taunting me, I report them. Of course, any reputable guild will instantly kick them out for causing issues with other members, regardless of Mythic's involvement.
The best answer is: find any reputable decent guild (there are tons), ask the few players that are being offensive to stop, and report the ones that refuse.
You will end up with a cleaned up guild and the respectful environment which you (and all of us) deserve.