Diversification is the key in this day and age, such that when a customer comes in to buy a dress, they may buy those items, but hopefully do additional purchases and leave with curtains and windows treatment appointment. Additionally it doesn't matter what category one sells to -- B2C or B2B -- as long as the sale happens, and that is what ultimately matters, that they are selling, whether in bulk or a single piece, the sale is happening. They don't have to be #1 in anything, as long as they are selling and making money overall.
I am not sure parking lots can save the malls. Attractive parking lots with nicely planted trees and garden blocks where people can take a stroll would certainly add to the attractiveness of low/mid tier malls.
What can save the malls is the stores inside. Foot traffic can increase when department stores hold events such as cooking demos and events, free fashion shoots with real people inside the stores, make-up events, etc. Of course all this requires space within the stores, and that is why it would work more with department stores, I think.
When there is wide scale use of a product, and a product that is successful to begin with, it can only help the host which is Penney in this case. I think this, coupled with the service side of Sephora, and them also upgrading their salons will only increase foot traffic more. A woman can go in, get her hair done and makeup as well, and pick up a nice dress on the way.