Having played both sides of the quest, I have this to comment.

1. I′m a vampire hunter, and my first reflex when I awoke Serana was to draw my sword and hit her. When she recovered (because she′s essential) we talked.

Where′s the option to kill her? I know it will ruin the quest but should be there, and when you choose the DG option and speaks to you at Fort Dawnguard, a "you can kill her" or so to Isran would be fine too.

2. Again, when I finish the DG quest, if she doesn′t want to become human.... die bloodsvcking thing!

And.... she′s super essential, immune to console command setessential, haven′t seen any other NPC like her. I can kill all skyrim but her

Enough Serana.

Volkihar Castle

1. Few more options when you defeat Harkon, like releasing the cattles. It isn′t possible to be a moral vampire?

Vampire Lord.

He′s way too slow changing positions spell/melee and when you select another power, it takes time. Also the known bug where it doesn′t hit on melee has to be resolved.

Werewolf: I gave Harkon 3 beats before he died, he was unable to hit me enough , whenever I caught him his life would drop near zero. Good work on this beast. Playing on Expert

One thing: Legendary Daedric GreatSword deals more damage and is lighter than the Dragon Bone one. This must be corrected because well, the DragonBone Sword isn′t worth

Well. Those are the major technical issues I encountered, great work out there.

From the game files it seems that the MQ for Dawnguard could be started by just walking into dimhallow, but it was scrapped for some reason. It would make more sense by doing it this way.