In general most low shank feet should work on your 15 clone. The only times I have had trouble are darning / embroidery feet with spring action. They usually work by a tiny finger touching the needle clamp, and for some feet it can be the wrong angle. I have managed to break two darning feet which in theory were low shank, but not made for the specific model. Unless you find a box of accessories belonging to your line of 15 clones, it will involve a certain amount of trial and error until you find one that work. The solid cast ruler feet for quilting usually work fine; equally so for generic walking feet but there are walking feet made to work optimally with the narrower feed dogs on the old straight stitchers. Tension is relatively easy to set on these. Bobbin tension is all about thread thickness, and everthing else tend to be light adjustment of the upper tension dial. I have to admit, it was a major fuzz for me until I got the hang of it.