A bit further explanation of the needle hitting the plate. The needle has to come completely out of the fabric before you can move the fabric for the next stitch. If the needle hasn't cleared, it can be deflected (bent) and so it hits the plate. If you hit the plate with the needle, it can throw the machine out of time. What foot are you using? Viking makes a spring foot that holds the fabric down when the stitch is made, minimizing the possibility that the needle will be trapped. My Viking has a special setting for this foot. If you are having so many issues, I would see if there is a FMQ class that you can take. I think an actual class on FMQ is really helpful. It's one skill that really benefits from hands on instruction.