Now the I liked the terrain though it needed more variation. Since you only used three types all over (Exception of Blight, Cobble path & Crops, yet again these weren't really used that much) I hope you see my point about this one.
Now some of the bridges was really weird(You can see screenshots), I was actually like saying to myself "Did this guy forget to check these things or was he high on crack or doesn't his sight work well". Also I believe you have made the map itself too big since there is alot of space which isn't used.
And now here comes the one which takes/gives alot of my points for terrain. Its the work with lower/raise tool:
Now you have made some insanely huge hills at some places(When you look ingame) and also the water!! you have made the blizzard cliff version which looks just horrible and also you have used blizzard cliffs when you can make some awesome terrain out of raise/lower
I recommend these tutorials for terrain improvement:
Lake/Water(Pretty ones)Overall terrain improving