First reaction: Nice map, if a little bright on the background
This is me, but I'd dial down the background colour a little - maybe a sepia-like tone, such as a light tan colour? I think you'll find that a little easier on the eyes, and it's dead easy to achieve - change the background colour - that way, if you don't like it, you can change it easily!
Next up: I notice that you state in the blurb "History: Middleton has been built and rebuilt in the same location several times" - with this in mind, maybe some of the newer sections of the town have, say, cobblerd or maybe even bricked surfaces (a cross hatch or similar filled polyshape per section of town) in the lower sheets (CC3) would do this reasonably well, I think.
Regarding the addition of cultivated areas outside the town itself, there are fills for polyshapes, such as "meadow" and "farmland" (the latter might be under another name - I'm not at my own PC right now!) that should allow you to do this!
That 's it, so far
As I said - nice map!