As far as your bus leaning to the left, it could be bad body mounts (easy fix), or a bad front suspension. Or, it could just be a factory defect. In the mid 90's, Chevy did the same thing to the S-10. A defect or miscalculation in the frames made the truck lean a bit to the left. I have a 96 S-10 and it's always leaned to the left. I call it my "gangsta lean".
Nothing you can do to fix it. If it drives straight down the road, I wouldn't worry about it.