So i have a werewolf and a vampire character, i was thinking of having them join the dawnguard. However would they have to be cured before joining the dawnguard? Or can they stay as they are?

no ones really sure yet, but i would hope not.

I don't think there's been word about that, may have to wait for it to be released.
I'd guess that Werewolves are fine, Vampires? Not sure.

Since they are Vampire Hunters, my good guess is if you are a vampire - you're go through some kind of a cleansing in order to join them

I believe that, since there is a way to cure your vampirism in the game already, they would either have you do that, promise to not feed on any of them there, and if you do you are kicked out and have to go through a reentry quest, or you just won't be able to join them as a vampire.

I would think you'd be fine as a Werewolf, but not a Vampire.

Lycanthropy is hard to prove, so is vampirism. Most people get along fine with either disease until they get caught feeding or transforming.

My guess is that your find unless you change or go too long without feeding. In which case, I wonder if they'll take you back after seeing you...

I'm not sure on either but I feel that they would put you through some kind of cleansing or tell you to get cured and then come back. I just wonder if you are a normal vampire, do you get to transform then.

I doubt it, since you are a vampire to begin with. Vampires in a vampire hunting club is silly

Would make sense to be able to join, as it increases the options to roleplay.

Got to keep in mind a cure to vamparism is not exactly widely know, if anything differs in form as well.

Actually plan to join them as a vampire, with the idea of bringing damnation to the kind that cursed the charter.

Feeding on them as well will make it quite interesting. Gives the idea of Hellsing.

Possible for a werewolf as a werewolf is treated as a different character right now I can walk Whiterun castle as a wolf rip The place apart Every non essential npc run into an ajoining with no one about change back and when the guards finally catch up they are all "you are trespassing that's 20 bucks"

Can the hero of the imperial army join the Dark Brotherhood and ? Yes.

Would be cool if you could join them as a vampire with the intention of destroying them from within.