No, this is the right place to post.. Map Making help is pretty much everything related to making maps (mostly at least).
Anyway.. those water edge tiles are not part of the map. They are statics, and exist in the statics file. This is why when you looked in WorldForge you didn't see them. Use InsideUO to see the difference between the landscape (map) tiles and the statics tiles (Artwork button).
I'm not sure if the merge program does the diff files for the statics (stadif0.mul, etc), but if it does, then you can use UOCopy to get those as well. This would be the "copy statics" part of it. This will create a wsc file that contains the water coast tiles and anything else not actually part of the map. You'll then need to freeze this file into your statics to be able to see them (Or you can import them into your world file, but that is dependent on the server you're using).
If the merge program cannot do the statics, then you'll have to manually add those statics tiles as items in game, then freeze them.
As for the rest of the questions, they don't belong in this forum.
-Ryandor