I've always wanted to write a fic where both Alistair and Cailan lived and both fell for the warden and she was like wtf do I do. lol & cool ill shoot you one now!
Oh my stars. Write it write it write it!!! I need to read that now! 
Their is a letter? I never got the letter shocked. Also have yet to get Sesbastin attcking Kirkwall war table mission.
Not very sure about this. I'm going to check, ain't Zev supposed to be writing a letter on War Table? A friend of mine told me that she got a letter from Zev (her warden romanced Zev) indicating that he's still fighting beside her or something like that. Wait I'll try to get confirmation.
Not a letter from Zevran himself, but you get this snippet in the HoF's letter if Zevran was romanced (if the HoF is alive, of course):
Part of me wishes that I could help your Inquisition more personally because the danger of Corypheus and the Breach approaches the threat of even another Blight. Regardless, Zevran and I have our own battles to fight, and I can only offer my confidence that you have matters well in hand.
And then Zevran doesn't appear in the Crows operation chain at the war table (which he does when not romanced), indicating that he's off with the Warden.