The Legal Department of any company that makes and/or distributes a preparation of bacterial spores (like Bacillis thuringiensis of ANY strain) will insist on all those warnings for the purpose of minimizing its risks. All Bacillus species form spores and, if one gets enough of them in his body, he could develop an infection -- maybe even a massive infection leading to septicemia and fatal shock, renal shutdown and generalized organ failure.
These spores are made to germinate and grow into full-fledged bacterial cells that produce chemicals -- the toxins -- that will kill the wax moths, which is why we buy them. Bacteria don't mean any harm; they just want a nice place to live, and it could be a careless beekeeper. The toxins can be very dangerous -- for example, that produced in tetanus by a different spore-forming bacterium, Clostridium tetani.
Treat the preparations with respect, but don't panic. Zillions of bacteria are already alive and well in our houses, and we don't get sick because we wash our hands.