First, want to awesome, as Bordo did!
I would like to ask that the shallow water be given some higher friction value or something (similar to how Alien Biomes mod does for like snow covered land) so that movement speed over it is slower (would seem a bit more realistic?). I ask primarily because I've always kind of wanted to use waterfill for a moat, but have always felt it a tad too "cheaty" for defense because it's a barrier that biters can never overcome. But having movement speed over shallow water be the same as normal land makes using it serve no real purpose for this.