I'm no expert, but here's the best I know. In terms of hairsprays, it would depend on the propellent. "A study by Du Pont Labs revealed the freon content of propellents for hair sprays and spray deodorants to be dangerously high, and the particles in these sprays are often so small that they can penetrate the lung tissue and be absorbed directly into the bloodstream. In studies done by heavy spray users, all those tested had precancerous lung cell changes" (Fit for Life II: Living Health, Harvey and Marilyn Diamond). The problem is the author does not give a number next to what they write so I can't go back to the reference pages and easily find the actual studies they say they are paraphrasing. The authors do recommend using nonaerosal hair spray or mousse. Also, keep in mind the book I quoted is out of date, written in the mid 1980s, so the propellents in hair sprays may have changed since then.
Talc is a carcinogen. I've had airbrush makeup done once to myself for my sister's wedding, and even though they did the best they could to not spray it directly in my airway I still had some temporary issues with the breathing, but then used the rescue medicines and I was fine.
Doctors in general are not trained to answer the types of questions you are asking, in my experience. They are best at doing pulmonary function tests and giving medicine, but not necessarily at determining what is causing or triggering the problem. I tried once to talk to a PCP about which filters to use in my home, and could tell he was not interested. In addition, a respiratory therapist I know had a patient leave the hospital, then come back not being able to breathe, then they stabilized the patient. The patient went home and got out of control again and back to the hospital. The doctor assumed it was the respiratory therapist's fault or a lack of medicines. The reality was the person was having their home redone, and it didn't even occur to the patient that could cause problems....most of the time, doctors just don't think in those terms. Your questions are very good ones, though.
In terms of rubbing alcohol, I react to that with breathing problems. In terms of if something is safe, a lot depends on how much is inhaled. Technically speaking, just using a car makes the air less safe. There is not a strict line between "safe" and "unsafe" levels.