>>28246332To go back, choose the "Back" option when you get to the stairs. You can also go back by going to the left exit of a town. It isn't possible on the SNES version or after a certain point in the game.
If I remember correctly, items don't appear on levels you've already cleared(though monsters can still drop items). But it's pretty handy if the shop doesn't generate the items you want. You can also get around the no-item-generation restriction by going forward and then going back, because leaving a level by choosing "Back" doesn't count as clearing it. Or at least, I'm pretty sure that's how it works, it's been a while since I last played.
Much like the storage system, it's a way to make the game easier for new players. If you want to grind for items and money, it's possible. But items alone won't take you to victory, and it's not difficult for an experienced player to clear the main dungeon with no storage and no backtracking.
If you're really having trouble, try throwing money. If you walk onto money by holding B, then use the swap command to swap the money into your inventory, you can throw the money at enemies to deal big damage. Of course, the money can miss, and you won't be able to buy as much, but having a way to semi-reliably OHKO strong monsters is very valuable.
