Exit spots on each dungeon level are generated at random. You have to have "Move-Find Item" equipped to find the exit, as well as the for the hidden items as well. As for the items, the lower your brave, the better. You chances of finding the better of the two items is (100 - Brave)%. So if you have 15 Brave, you have an 85% chance of finding the good item, and a 15% chance of finding the normal item.