The thick lanterns kind of bugged me, so I tried making an alternative one. It's attached. It has some small brushes that get garbled, though, so now I'm looking at the compiler tools to see if I can fix that issue (it's been bothering me for a while when trying to do small details).
I'll try to post more feedback later.
One general note: For as small and simple as the map is, it's surprisingly easy to get disoriented.
For example, in ViciouZ shot, the deadend area looks like a path, and when you're coming in from the angle that screenshot was taken, it's not immediately obvious if the flag is on the left or right.
Also, the light wood bunkers in the middle look really out of place to me. They don't really look like anything, and I'm not sure how useful they'd be in practice... they're just kind of there, and look weird.
Oh, and the double doors look really bland (do an image search for "castle doors", and I'm sure you'll get plenty of inspiration). Also, they technically wouldn't be able to open with as thick as the wall is (top of the door would collide with the arch).
There are some areas where the transition between rock and brick is unnatural/nonexistent.
Lots of little things that I need to make a demo of or something to point out, but I really need to get to bed now.