Now that you are at 4-2 you might as well just farm the reaper (weak to fire) and buy healing items from the singing merchant in 3-1 until you rescue the Saint from the trap in 4-2 and confront Patches to get him to sell items to you at the Nexus for a good price. The imprisoned Graverobber Blige from 4-1 sells fire arrows at the start of 4-2 if you care to go that route.
1-1 only has Ostrava in need of rescue, 1-2 has a locked door to the dungeons with Biorr (by the boss gate), and 1-3 has a locked fence door (by the fountain) leading to a tower with a bridge requiring an Officials's Hat for passage and Yuria on the other side. Ostrava is in need of rescue every chapter.
P.S. There is a ring hidden in 3-2 at all white tendency that makes it so that you can move through the sludge of the septic tank of 5-2 without being over-encumbered (unable to roll). If you avoid dying in physical form in World 3, beating the bosses of 3-1 and 3-2 together with invader NPC at 3-1. Remember to kill your physical self at the nexus to avoid moving toward black world tendency and reenter worlds to trigger change in world tendency.