I just wanted to encourage you. It sounds like it all needs some tweaking but I think in the long run you'll get the hang of it.
Polly thread like OMNI
http://www.superiorthreads.com/shop/...EvGRoC-QXw_wcB
tends to work really well for my INNOVA machine. When I run 100 percent cotton it breaks way more. There is a definite learning curve to finding the right tension and it takes some time. Having the timing set the right way on your machine and having the right places oiled are all very important. The type of needle ( I usually use 18), how sharp, size and the way it is put in is very important. How the machine is threaded.
Best wishes. You have a really nice machine. I hope the issues will be resolved soon.