Looks great so far. Lots of work. I think you did a great job on the buildings.
Those wall towers are absolutely gigantic, like as big as the cathedral. Which seems excessive to me. And there might also be smaller towers also interspersed along the wall (or not, there are plenty of city walls without, but this looks well fortified so they'd probably opt for more). For the pavement inside the city I'm assuming that all the slightly darker grey is paved too? For the avenues you could add bits and bobs to it to read more realistic, things like adding thicknesses to it in places or filling in town squares, or cutting/round the corners of some of the turns (like where you have a building doing that but not the pavement, I see a few instances where the buildings do it but not the pavement around Marketplace and to the left of Mead Estate and one on the NW corner of Pilgrims Place). I do think it's kind of odd to have all inner roads simply terminating at the walls, I'd think one or two swing around and follow the wall to meet up with others on the edge, but that may just be a bias of my own.
Regarding the laying of smaller roads like outside the city, you may find it helpful to switch it up by placing buildings before making some of the roads. I found it really helps me make some parts look like they grew more naturally. You have to use a mixture of course, some roads need to be layed first, but some can be done after. As for paved roads i think there would be far less use of them in the countryside, paving is pretty expensive, so keep that in mind. I think in many cases they'd be the last thing to be built up when people were so annoyed with the mud they finally decided it was worth the cost.
I think the fields look pretty good, and I know they really add a lot to the realism of a map. You might consider varying the colours a bit to indicate different crops which also adds a bit of realism, but it's not necessary, and I know they take a hell of a lot of work to put in at all. It sounds like this is a pretty low lying flatland area, so the farmers (or rulers using forced labour) might have built irrigation canals.
Edit: It may not matter but you described a rather wet area it seems to me, quarrying stone might be an issue, meaning it has to be imported, if that were the case they'd probably opt for brick or more use of wood. Not sure if that's relevant at all or not.