Well, it's very nice to see this being used. I like your ideas and it has great potential. Along side what Zel said over the tree-water overlap (which I think you may have to create in block editor - ...I don't remember making that) I have noticed, however that your not always using the overlap tiles, for example:
http://img220.imageshack.us/img220/1...remblemyx8.png
You really should do this for consistency. If you get your maps perfect, it'll be great. Good luck
~GC