So there is no once and for all answer to what's bad and what's good. At the same time, I detect a note of hysteria in general discussions. It is well to remember that ceramics, pottery and glazes are old, very old, in the experience of humankind, and we haven't been killed off by it yet. When we discuss risks and toxins, we tend to do so with emphasis on the dire consequences, without regard for the fact that most of what we are discussing has been in common use for a long time. There is an experiment which has been proceeding all the while, called life, and the general outcome is not wholly bad.
Life expectancy is up, on the whole.
We should not get mesmerized by the problems, but try to incorporate them into the whole picture. Toxicology as it is now practiced is complex. Most of the easy problems were solved back in the 19th century and before. We know that strychnine and cyanide are generally bad for you, although the former is used as a helpful drug. The purest water, completely deionized, is not good to drink in large quantities, because it upsets the salt balance and tends to do bad things to the gut.