Loot chests and quest NPC

I think the fact that NPCs land on the roof has to do with the fact that when the world is loaded, everything basically falls from the sky. And it does so in a specific order.

Yes, it would be so cool if players could determine the pathfinding themselves in the game and also coordinate the timing.

NPC's getting on a roof is because the npc can get into a place withing 4 blocks, but the pathfinding is sometimes a little glitchy and it will walk into a place were it is withing 4 blocks, so it will teleport to the roof. So yes better pathfinding is really a thing we really need. NPC's not leaving areas was one of my old suggestions too, we also need that, so we can maybe add something like the area tool but then make it for npc's so they can't leave that box.