I have given the OP some benefit of the doubt by responding to his prior threads, but came to quickly realize that he starts threads just for the sake of it - there is no real substance there. *Clicks "Block Member"*
Wife and I stayed in Grand Hotel Santa Lucia on Via Partenope - minutes away walking to all the shops you mentioned. Hotel and location comes highly recommended. As far as shopping goes, prior Napoli threads have all the information you may need. I'd suggest to start walking on Via Chiaia and see what gems you may discover. Cannot give you many food recommendations - Naples was one of the last stops on a long Italy trip and by the time we got there we were tired of...
In my experience, Piombo jackets run slightly slim for my body. After handling a few (and not being impressed with fabric/construction), they are meant for slim/skinny body types. If that's you, "true to size" should fit well.
I like a lot of brands but get excited by only a few that are not readily available. On a recent trip to Naples, for example, I got excited when I saw the Gallo store and ended up buying some great socks. Just a few days ago, I got excited when I saw a beautiful, brand new mauve Breuer tie at NM in the clearance bin for $15.