Having completed that huge 'Golden Tapestry' I can contribute the following!
1.Kingstar metallic thread is by far the best, I have used over 2000 metres of the stuff with never a breakage or a twist.
2. I use it on one of those 'Prym' metal thread stands, and stand it at least a metre away from the machine - this stops the thread twisting which sometimes leads to breaking. It can be a bit sniffy if you use it on the machine spool holder.
3. I use metallic thread needles. You will find the needle hole is longer, usually made of 'harder' material as the speed and friction of the thread can sometimes 'saw' into the needle hole and make little nicks.
4. I use Brother embroidery bobbin thread - is fine but strong.
5. Slightly loosen the tension.
On a creative stitch course I did, we had to compare metallic machine threads, and Kingstar came out ahead, for being easy to use.
Hope this helps.