My thought is to perhaps try another teacher, if you really need to. I am self taught too other than my mother decades ago when I was 11. You will get a whole different set of answers with someone else showing you something, just as you do reading different books and magazines. I have done both pre-wash and no pre-wash and goodness there is a difference. Most fabrics I pre-wash because I sometimes want the receiver to see what the quilt looks like before the first wash and dry; I have pulled bobbin threads up, when it doesn't make a difference in the quality of the quilting I am doing, nor compromise the design of the quilt; I love and prefer bias binding, but have done crossgrain also. Works for wall hangings without a problem, and doll quilts; I prefer a walking foot. Have done it without also. The thicker quilts I use the walking foot because it helps guide the quilt through the machine more evenly with very little effort from me; I have to have the extra flatbed table area for quilting or sewing of any kind-except garment sleeves. What's up with saying don't use it? And there is nothing wrong with your Singer. If it sews, works for you, and does what you need it to, then my goodness use it and enjoy it. Don't let anyone talk you into spending more money when what you have works just fine. Every quilter is different and you will have your own style. I wouldn't take what another says as law. Make it your own.