1) It's been a long time since I played a Bioware game, but in all seriousness I don't know very many LGBT characters in any of the games I play.
2) Don't really think there are too little, nor would some more gay, lesbian or bi characters be a bad thing. Don't really care as long as things are handled tastefully.
3) I don't play enough games over the entire spectrum to be sure. I know there are quite some gay, lesbian and bi characters but any good character doesn't wear their sexuality on their sleeves. I don't think transgenders need representation so that's not an issue for me.