Can I place multiple traps on the same tile?
If 2 traps are on a tile, and a 1HP enemy wanders onto the tile, are they both triggered?
No, the traps trigger individally until the enemy or the traps are gone.
If 2 traps are on a tile, and a 2HP enemy wanders onto the tile, will they kill the enemy? What if one is a trap from the hunter and the other isn't... Will I get a food?
Yes, the first will trigger, deal 1 damage and be removed, then the second will do the same, killing the enemy. The order of triggering is decided by the players, and choosing to have the hunter's trap deal the second damage would produce a food.