[GAME] Collaborative World Building Dwarven city as a start

[(E)]

Collaborative world building
Detailed here and here are some thoughts on how the farming systems might work for a dwarven city. It has been suggested that this might make an interesting setting seed for collaborative world building, so here goes.

Using the dwarven city of Knurlkyth as a start point, let's see what evolves.
Answer a question ask a question format.
Any mistakes in continuity that crop up might also be solved by asking the right question.
Feel free to expand beyond just the one city.

There are a number of switches in the write up that might be best selected as a side effect of other answers or as standing questions for later in the process. These questions are largely unimportant to the narrative but will likely change the population. To separate them from the normal questions they have been lettered.

A. Do the dwarves have access to relatively clear glass or a substitute?
B. Do the dwarves have access to “new world" crops such as potatoes?
C. Are the dwarves technically inclined enough to develop the seed drill earlier than humans did?
D. Do the dwarves farm fish?
E. Are minerals mined for agricultural use?
F. Are insects used to make better use of resources for food.

Question 1
The highest point in the city is about 5km above sea level. How deep are the mines beneath Knurlkyth? Why?