I thought the same, this is heavily show. No staircase? Also, yes Castle Black famously had no defences on the South side as it doesn’t expect an attack from within the realm. And of course, when that grill was never in the book as it has no defensive purpose.
You must not have caught the part where she said how much she struggled to get the white to make the wall. Appreciate the work done, I’m sure that with unlimited money and time she could build all of Westeros