Here's an update of my build so far (for anyone who cares):

The keep is finished. I'm working on a port at the bottom right. The port will have a staircase going up to level ground to connect to my walkway and have a port-master's house and fisherman's house near it as well.
As well, the structure to the far left, in the middle, is an entrance to a gigantic library that I've been tunneling out. The dimensions to the library are roughly 26 bricks wide, more than double that long, and should be about 9 bricks high.