1. Yes, ozone will kill the mites/fungus in your clothes and other belongings (gas penetrates better than vapor produced by fogging).
2. Haven't tried using the air duct method. I shock treated room by room. You can do both.
3. No real need to wear mask or have a timer. I just held my breath before entering the room to turn off the generator/open windows and then leave the room immediately. You can enter the room in about 30-60 min. with no harm to you.
4. I have tried many, many internal and topical products and they don't work. Don't waste money on those products. Zapping using the method I suggested will put the skin infection under control in a week or two (but completely eradicting the condition is another matter).