I have this same machine, only had it for 6 months or so. It sews perfectly until I try to fmq and like you it goes nuts. One thing I found is that inside the bobbin compartment is a little hook with a thread cutter in it. You put your bobbin in and then pull the thread around this and it cuts the thread off. This was new to me because any machine I ever had you would use the hand wheel and then pull the bobbin thread to the top of the machine. You must use this little contraption and not try to by pass it or your machine will not sew correctly and create awful birds nests on the back and even pull the fabric down into the machine. Also when doing fmq reduce the pressure on the foot by using the round knob on top of the machine to back it off a little. Your owners manual will explain more about that, but that did help me a lot. Also one other thing, Make sure when you thread the machine, the thread goes thru the needle left to right. The owners manual for this machine in my opinion is not very clear and right after I got it I found out I was threading it inorrectly. You are very correct in that the machine speed and how you coordinate your hands when doing fmq is very important. On that one you will need to practice and get the feel. I have 5 other machine and have been sewing for over 40 years and this machine is definitely different. Just practice and try all the suggestions here posted by others. Most of the other comments I can relate to and have tried myself. Stick with it, get some scrap fabric and practice it will get better. Good luck