If I could buy a large abandoned mall, I would absolutely love to turn it into an affordable community housing complex where shops can be set up alongside the housing units. There's definitely more than enough space in any mall I've ever been to in America where you could easily renovate and turn stores into either single unit housing or maybe 2-3 units (big stores like JCPenney or Sears not included in this count because you could turn those into tens upon tens of units, assuming they're as big as the ones at the mall near where I live).