I'm afraid I only have information with words regarding the errors.
I was running away from a guard and entered the three-way shortcut/hiding place by the thief mice. I went inside and at the puddle in the middle, I fell through the map and had to reload my save.
At the tower near Silas, right outside of his post and up, the stairways glitch about halfway up to where I can actually enter the stone stairs and middle supports. It wasn't game-breaking, but it took me out of immersion for a moment. This one is a low-priority bug, seeing as it didn't break anything or make me fall through the map.
The eel monsters in the sewers tend to do the bug where they are constantly aggro'd until you reach another enemy and aggro him then hide.
At the three-way tunnel by the two thieving mice, there's a trap door that allows you to go by the gate. I found an exploit to where if you forget to take off the bucket from it, you can climb to the top and then jump, quickly pressing A to pick up the bucket and teleport it through the trap door. You can then climb up and open the trap door normally with the bucket staying down in the hidden passage.