Thanks! Yeah, the game is a bit too long and big, and the outside areas are very big, i admit that. The reason the enemies are only in the dungeons is that they aren't saved, so if they were in the overworld, you would be able to get more xp than you are supposed to, which does break the story progression.
As for the old man damaging - it's not supposed to happen, but it is a hint. You may or may not need to attack him for the last xp...