Mana / Healing Potions - I kept Mage in Paramedic role throughout and always used the focus spell to replenish his mana. You can replenish the others by fighting easier monsters and just letting them defend. It is tediously slow but can be done. One would think you could as easily purchase sela potions with healing potions in any town, but, alas, that is not the case. Not sure if that's done deliberately to add to the challenge of the game or if it keeps within the magic drought theme of the game.
Coconuts - The monkeys with the coconuts should be visible on each of 2 islands. Are you landing on the islands and then wandering around outside the town proper?