I played around with the shoreline code a bit for this map. I have uploaded a
diff and the
file if you are interested. I basically made the beach slope gradually and moved the dry/wet sand terrain transition underwater because it looks ugly (the blending in the engine should be fixed really).
Also in the process I found that the height for tiles is specified for the corners which, based on your code, I don't think you were taking into account. Because that is not the way I want it to work I patched the rmgen script so that now if you set
TILE_CENTERED_HEIGHT_MAP = true;
using setHeight/getHeight will do it for the center of a tile. You will need the latest svn for this to work though. If you don't have the latest svn it will just have the height map shifted by half a square towards the bottom left of the map, so it is safe for Alpha 8 users (most noticeable that the right hand beach is larger).
Edit: Just noticed my previous diff was in the wrong direction, link is correct now.