Autonomous players: three impossible quests unblocked

Analysing quests worked hundreds of times without ever completing revealed three flaws: an item to fetch first, illusory loot sources and an underwater target. All three are fixed.

Item to fetch first: some quests require bringing an item to a place (remains to lay on a grave). Players went straight to the grave without ever fetching the item. These source items are now sought first.
Credible loot sources: a monster dropping an item once in 10,000 kills counted as a source, so players hunted hundreds of bears for nothing. Sources under 5% chance (or far less likely than the best one) are discarded.
Underwater target: a crystal to neutralise at the bottom of a lake was never reached, as paths do not go under water. The player now aims for the surface above the target, swims if needed, and uses the quest item as soon as it is within spell range, without going into contact.