I think ultimately it comes down to how much deregulation occured.

If you go all the way and the FDA was replaced with companies who offered to test and "approve" drugs for profit then I think it is difficult to establish a full trust relationship with those entities.

You mention the FDA becoming advisory; that could become a good compromise. However there is a danger that people would simply ignore the dangers and, at some point in the future, suddenly realise they had done something terrible to themselves :D

A balance is crucial; I think we actually have it in the drugs industry, but perhaps there is room to make modify as well...