Sorry you're having so many problems with your Ute. I haven't experienced the steering issue at all; I wonder if it's something specific to your bike? I find that the bike handles nicely even loaded down. I just got back from a 3-mile trip home from the grocery store with around 70lbs of groceries, and the Ute handled like a champ, even up a steep hill. The more I ride the Ute, the more I love it. (With the exception of the single kickstand!)
Where did you attach your front panniers?