Actually, I thought the hacky-slashy combat was a huge improvement over DAO's. I could have done without the waves of enemies that appear out of thin air though. Perhaps somewhere in between?
The ending of DA2 was a problem too wasn't it? Though that was more a result of the multi year story structure that required three separate and largely unrelated endings leading to the same anticlimax.
As for what I'd like to see, I think playing as a Seeker recruit in Orlais this time around would be a good direction...though with the Mage-Templar war on it might be tricky justifying being able to play as a mage. Maybe the chantry offer sanctuary and/or amnesty for mages (even apostates) willing to serve as a Seeker. Taking a page from the Grey Warden rule book perhaps?