The question on performing your own inspections and certifications for safety equipment is a two edge sword. With all things considered, we self inspect and certify all our safety equipment including our 6 person liferaft.
As far as the PFD is concerned, I have pulled the inflation handle and let the thing inflate while I was wearing it. Let it stay inflated for a few hours and repacked it replacing the cartridge. Ours don't have the pill so that part is a non issue. I understand that inflating it is suppose to put some stress on it but its the best way I know to prove it works.