If you haven't already, get yourself some good quilting gloves, like "Machingers." It sure makes a big difference.
You should be able to change the needle position. On a lot of machines, when you're on a straight stitch, the stitch width button is what changes the needle position. But it's hard to say without knowing more specifically what model your machine is.
Machine quilting is just like anything else... practice makes perfect. Just keep practicing.