Well, some of this speculation is Wolfschadowe territory but I'll go where I can with it and let him fill in whatever else he might be comfortable with.
I just remembered that the eighth name has already been revealed in another "open forum" thread so I'll go ahead and i.d. her again. "M" is Muirghael, and I'll let you speculate on the origin of that name.
I think it has been pretty well established that the game will eventually include a total of 8 possible romantic partners for Brad. How the various partnerships might evolve and end up for him is a big part of the "Erotic" part of Brad's Erotic Week. They are listed across the top of the score panel on the screen, although some are still "grayed out." Wolf has been pretty clear that a "happy ever after" ending is possible with some of the choices but rather more problematic with others.
So far, we have met and had a chance to "romance" Emily, Faith, Natalie and to a very slight extent Serenthia, although Brad doesn't know it yet. Of course, we can't do all the girls in any one play-through, thus the replay value of the game. The upcoming "inclusions episode" will add two more, with whom we have already had some opportunities to start building relationships but haven't had a chance to fool around. You will have noticed several conversation "hooks" in some of the scenes suggesting there is more to come in a future episode.
That leaves two more potential lady friends, as yet unknown and unmet, to make eight. Blatant speculation has centered around Samantha (the waitress at Faith's bar,) the mysterious Lorien, whom we met in one of the bonus scenes, the even more mysterious Muirghael (who so far is nothing but a name) or possibly someone else we have not yet met. There could also be other characters introduced along the way beyond the eight.
I think that goes as far as I'm comfortable with. As for other races beyond humans, that is all speculation so far. There is some pretty strong evidence for at least two other kinds of beings and the use of an elven language in the bonus scene pretty much locks that one into the range of "probable," as does the appearance of certain physical features noticed by sharp-eyed players and certain "sneaky" abilities possessed by at least one character. There is also strong circumstantial evidence for the existence of the third race in some of Brad's experiences. Which of the girls fall into which category will be revealed as the game progresses.
There is a lot more to this game than just trying to bang the babes.