Hi SewnSo,
My machine is like yours. It has Viking plastered across the front, with different plastic front, but is the same machine, thread path and all. It quilts great. If you have traced your threads correctly, it should sew.
If you have the tension set, it should sew without breaking.
If you have the correct needle, it should sew fine.
HLX5 is what was shipped with my machine. Schmetz has this needle as a quilting needle in two sizes: 75/90 as either 11, or 14 depending on the fabric you are stitching.
Check your thread tension again. If last resort, have a tech inspect the tension disks to see of some thread has gotten stuck in there somewhere.
I am sure you know to keep it oiled as someone has stated earlier. Oil after every few hours of sewing, when you get it sewing :-)
When you get this straightened out, you are going to love this machine.
Good luck! If you want, send me a picture of the machine after you have threaded it. I will try to see if the thread has gone wrong somehow.