I drink approximately two cups of kefir per day. I cannot comment on the taste of store-bought kefir as I have never tasted it. I understand that the kefir grains can be a little sour tasting at first, but then you get used to it. You can put nutmeg, cinnamon and flaxseed oil for taste (I love it with or without the spices!!).
Regarding the list, I am happy if it helps you : ))