The fact that she is your slave is enough. Even if you're a nice master who treats her with respect you're still her master and that's too much for me. Yeah, you could be a douche to the LIs in other games and even kill them, but at the end of the day they make their own decisions and are their own people. Vette is yours.
With the Revan thing -- I didn't like that Revan was a man. I didn't like that none of the characters really got closure (Mission and Big Z opened up a shop? Really??). I didn't like that the Exile was reduced to this weak little school girl with a crush that is killed off like a minor side-character. I didn't like that Revan was a boss fight. I REALLY didn't like that book. I waited almost a decade for an ending for the characters that I grew up with, and it was bad.
She isn't your slave if you take the collar off and let her be her. Seriously, did you even play the game? Not once during my play through of the Sith Warrior did I refer to her as a slave. My character made it very clear that she was free to go whenever she felt like it. Seriously, does the subject of slavery offend you? Why are you even here? Slavery exists in Dragon Age. You can do cruel things to companions and NPCs in Dragon Age. Your argument makes no sense, not as someone with a DA avatar on a DA forum.
Revan is a man, get over it. Just like the Warden is a Dalish elf. Besides, the Revan quests are optional. If his presence in the game offends you are goes against whatever it is you had in mind for him, simply skip it.
And the Exile is hardly weak.
Besides, we didn't get an ending to Revan's story. He kinda just vanishes at the end of the boss fight. Seriously though... You seem to get way too attached to characters that aren't even yours. You play as them and make decisions for them during the events of one game. Then it's back in Bioware's hands.
Not every character is going to have the ending you want them to have.
I wasn't. I haven't actually played the game. I'm just going off of what I've seen and read. What I've seen and read is bad, but I'm starting to realize thanks to Ryzaki and others that maybe what I've seen and read isn't enough. I'll look into it and see for myself.
OH! So you haven't even played it? Dude, seriously... Play the game or stop whining.