Phosphoric accid is what is in Naval Jelly. I would go to the automotive paint supply place in your town and get a product called metal prep.
It is a liquid phosphoric acid and it is used to prep stripped steel for painting on cars. You can use it in a spray bottle and it has directions on dilluting it with the appropriate amount of water. It's cheaper, faster, and better than naval jelly IMHO.
On the rest, I cannot help you yet. My Dad is bringing me a 26 inch stainless pan this weekend for parking and then I will have questions too.