that doesn't make sense that you are REQUIRED to use their templates. I use go daddy and they offered templates but I didn't use them because I didn't like the look. Are you talking about for the entire website, or just the shopping cart part. Unfortunately, I had to use a template for the shopping cart and it had so many restrictions so my shopping cart/checkout was created as a pop-up window rather than an integrated part of my website, if that makes any sense. So the entire website was created from scratch using dreamweaver but the shopping cart was added as a pop-up so you would still be able to navigate back to my website...The look is a bit different, but I wasn't able to do anything about it.
I'm not sure what your question is and I not sure if I added to your confusion but I hope things work out for you. I you have any other questions, I'd be happy too help if I am able. Good luck with your new venture. Oh-almost forgot--sending a little TLC your way also