I guess the biggest thing is that it must labeled properly. There are a lot of dangerous chemicals sold, there is nothing unique about Miracle-Mineral-Supplement that way. They are all labeled properly (well at least the ones with attorneys probably are!)
My husband works with chemicals and the way Jim worked the 28% is actually a 21.x% solution per chemical standards (it accounts for the other 20% of the 80% NACLO2 that is sold). Jim does mention this in his book.
The liability issues you raise are serious and not to be taken lightly.
Maybe a group of producers could get together and hire an attorney.
Of course, I would still like to hear from anyone who's purchased it from the site mentioned in the topic header!