Well, here are some ideas for the centre of the layout (and, actually, a bit of one of the raised sections). I've only shown one end and half the centre section so far because if nobody likes the ideas, then I haven't wasted too much time.
Here it is (with apologies for the rough and ready approach):

Some facts and figures to put things in context:
- each square is 1' by 1';
- a Steck house is 7.25'' by 7.25'';
- the fishing boat (
http://playmodb.org/setpics/5131.jpg) is 7.25'' long (this is as an example of boat that could be used; the yachts are also this length.
The rectangle at the left hand end is the raised railway section, as is the narrow rectangle running along the back.
The suggestion to use the space on the raised section for a row (maybe a terrace of four) Steck houses with a pathway (it could be grass) in front of them (c 2'' wide) and a fence along the edge of the board to give a row of clifftop cottages. This is marked A.
Turning to the centre, lower, section, there is 7' from the front to edge of the "cliffs" along which the railway runs. I'm suggesting 1' strip of sea and then a 1' strip of beach (the line between the beach and the sea needn't be a straight one, of course) and then a road (6" wide) dividng the beach from the fields beyond. This gives a natural transition from fields to beach and also allows access to the terrace of Steck houses (fishermen's cottages?) below the cliffs - marked B. Also at the left hand end of the road, there could be the dock ramp (
http://playmodb.org/cgi-bin/showpart.pl?partnum=30-22-4342) to give access to the sea for boat owners.
This leaves an area of roughly 4.5' by 7' for fields, farms, trees etc.
To keep things simple for the moment, I've not indicated where the railway bridge will go or the river. The river can get to the sea by flowing under the road.
Any comments welcomed.