CBRNE (Chemical, Biological, Radiological, Nuclear, and high yield Explosives) have the ability to create both mass casualties as well as mass disruption of society. Agents that are living organisms or materials derived from them that cause disease or harm to humans, animals, or plants are biological.
Working out won't cause fever blisters.
Trichomoniasis can cause a rash with red spots and itching, but doesn't cause blisters.
sunburns cause water blisters
Biological may be the answer you are looking for. CBRNe stands for agents used for warfare (biological warfare is an example). The acronym stands for Chemical, Biological, Radiological, Nuclear, and the "e" stands for enhanced (improvised) explosives. Biological agents usually are those that cause the symptoms mentioned in the question. However, there are some chemicals that can cause those symptoms from exposure as well, although they are less frequently found.
Friction can cause blisters, yes - however, many sexual diseases cause blisters as well. If you have blisters on your sexual organs, you should see a doctor to make sure it's not a disease.
No not all blisters are herpes. Some are just water blisters from chaffing, some types of eczema can also cause blisters.
No....
Yes, from where the leg meets the stump if it is not fitted correctly in can cause blisters.
Yes
Most certainly not.
Yes. Skin contact with boiling water can cause swells and burns, with may turn into blisters, and the blisters can cause scaring.