At the beginning of the game you could come up through the hatch in Mardaneous' house from a tunnel reached by the well. However, the ladder up to the hatch is no longer there once the orcs invade Aleroth.
The dire warning in the
lost items post was to keep people from file swapping when they just had to go back over an area with the alt key pressed, and when it was necessary, to encourage them to follow the procedure carefully and to save under a new name before starting. There were less warnings in the post in the old forum, and a couple people accidentally overwrote the wrong files without making a backup, and had to revert to an earlier save.
