Always test you FMQ on same fabric as quilt and with thread you want to use. Some machines like certain thread better than others so same on top and bottom should work better. I often use poly thread for FMQ due to the variety of colors. A contrasting thread for quilting should show up even it it not a heavy weight. Tension issues usually can be adjusted. I tried SID with clear on top and black on bottom and could not get tension right so black bobbin was not showing on top. I changed bobbin thread. Also "eyelash stitching" on bottom is not ususally caused by tension but by speed of FMQ. Small "eyelashs" should go away with washing or use but larger ones need to be removed and restitched.