The lack of "real" water is a shortcoming of FS 2 that harms its beauty and cannot be overlooked. But the delineation of shape of water is really a heavy task, especially in such places as the irregular shoreline. This difficulty can easily be overcome if the data of OpenStreetMap can be used. It will delineate rivers, lakes, shorelines automatically. It would also save a lot of trouble for GeoConvert. No need to do the alpha layer or other photo editing, which is very challenging and time consuming for many people.
This sounds quite cool, although I'm no pro