So glad you have it working now! Here's how I set my BSR up and it works like a dream.
I often use different weights of thread with the Bottom Line in the bobbin, but I thread it through the spring and use the original bobbin tension. I drop the top tension (it's just a temporary change so you can try it once and see--it resets when off) to 2.5 and the stitch length to 1.0 to 1.7, depending on the look I want. I use an embroidery needle or a large-eyed needle, to handle. I use a super slider. It is wonderful. I didn't have any success with the BSR until I did all of this. No skipped stitches, nice gentle curves, beautiful!
I even used metalic thread in the upper thread and Bottom Line in the bobbin recently for my daughter-in-law's bag, and it worked magnificently.