I do not know which version of the game we are talking about. If we talk about the latter, then the hatch in the UnderCity is located right next to the southern gate of the city. It's a sewer.
2 near the church, when you take a quest, you will find a guy who will give it.
That's because you went to the meat pit, I just don't know any other options for why the save was lost. In one of the versions, I fixed this moment, which is described in the post and the description of the update.
