This sauce keeps well in the refrigerator (perhaps thanks to the preservatives in the commercial BBQ sauce). I prefer to use one of the "thick and rich" types of BBQ sauce -- but I've also found it's good with thinner variotions. It's really a matter of preference. The amounts of ginger, garlic, and red pepper are scalable by taste -- I really like a strong ginger flavor and a lot of red pepper, but have found that some people may prefer less. You can also experiment easily with adding other flavors -- curries, onion powder, a T of Sake or dry Sherry, a dash of oyster sauce, and the addition of raisins are all additions that have worked well for me. I like this sauce best when made with the thick, dark type of soy sauce, used on very rare beef (either grilled or stir-fried).
Unfortunately, I have no concept of what the nutritional values are.