Just going to weigh in about the whole marriage thingy.
I played Dawnguard w/o any knowledge of it before starting (which is how it is meant to be obviously) so when I first met Serana and saw how she tied into the game, it was pretty cool. In fact, I'd go so far as to say that Serana made the DLC worth the money, just because of how she tied into the game. Needless to say, with all the stuff you do together, it is disappointing to find out you can't marry her, even when you are extremely nice to her, because it feels as though you are forming a bond as you develop the story and then it ends up with her being just another follower (powerful and unique but still just one more).
Yes, we all understand it's a game. Yes, marriage turns the game's characters into boring drones (which is more just shoddy implementation than anything, but it is bound to happen). However, the mechanic exists in the game, and all characters end up being boring drones at SOME point, and of all the characters you have the potential to marry Serana is the only one you get to know past a few lines of dialogue or "hey I did you a favor, be my wife/husband". I think it is to be expected that people would be disappointed.
The main thing I can't understand is... why did Bethesda NOT make her marriagable? Again, I don't think the, "she would be a boring drone" argument holds any weight and it seems as though it would be a perfect capper to the whole dlc, especially since
Spoiler you can cure her of vampirism if you aren't a pushy a-hole
the whole situation feels like Bethesda is giving us a raspberry and laughing their heads off. You could have told me that Bethesda has no interest in getting carried away in the domestic aspect of the game but... well, Hearthfire.