At first look the "shaft" appears to be 'different' from the rest of the map.

Also there stuff on the Common Sheet (shouldn't be any thing there). I would go thru each of the sheets and make sure what is on each is what is supposed to be there. Hide all of the sheets, then show each sheet separately. If something is out of place move it to the correct sheet as you go. Checking the layers the same way could be a good idea as well.

Looking at your city it seems to me that it is big enough that I don't think I would put in all the buildings. I would put in the important ones but not all. Then make closeup maps of the areas that need it. So if your party goes to the "Inn of the Old Sign" but there is no combat in the area just put a dot on the map with a label. Does that all make sense?

Yes more symbols! A uncovered half-track, then one with the 3 American soldiers shooting from it. (a "The Dirty Dozen" reference)

I have seen 1600s maps of Port Royal that show turtle pens that look similar to your pens. If you were to add some big turtles in the water that might work.

A thought, coming in to this late, is to check the flavor text in the Mistborn books by Brandon Sanderson. Which may point to some detail things to through in.

Volcanic dust on roofs, and roads for example.

Monson, Thank you, I did not know that, I have been procrastinating on building symbol files from them.