1 I have no input whatsoever on story. I'm happy to let the devs take me wherever they will as far as that's concerned.
My primary story goal for Thedas was met with DAI regarding the mage/templar issue. I wanted that (somewhat) resolved after having an entire game and a novel that talked about it in a big way. What happens after DAI is anyone's guess, but I was satisfied with the resolution we got in this game.
I wouldn't mind another Blight.
2 I'd really like to see Tevinter. Fenris and Dorian are my two favorite characters in the entire DA series and they, in addition to the tiny glimpse we got in the comics, have really made me want to go there and see it for myself. The architecture and style I expect to be as extravagant as Orlais, but with a different flare that will be unique to a culture that not only borrowed heavily from the elves and has also existed for thousands of years.
Unfortunately, I don't really have an interest in the Tevinter/Qunari conflict which I suspect would be a key feature in any sort of Tevinter story we're expected to play through.
3 I don't have any input on characters either. I was/am extremely fond of certain characters from DAO and DA2 and I stupidly worried that I might not like anyone in DAI. I've learned my lesson and am happy to leave all aspects of character creation to the devs and not think about it until I actually play the game.