The document says it all. Please give any feedback and suggestions you have on your mind.
I would suggest making the area between the coast and the Blue Fork dunes. Do mind that dunes are not limited to barren sandy hills, but include sandy forests too. This would tie into canon in several ways:Hey Dav
Approved from me - at least if I had a vote
One thing i'd like to adress are the roads though and one canon issue, spoilers ahead:
In the books Robs army marches back to the twins via Sevenstreams and Hag's mire, as the bridge at fairmarket is gone.
(Mallister joins the host at hag's mire, where Rob sends Maeger Mormont and Glover to seagard and to the neck.)
Meaning Rob is taking the army through the marches. Why would he do that?
Well at least on our server he has nice coastal road from oldstones to seagard and twins.
We also know as banty reminded us, there must be a road between oldstones and seagard as well, as caitlin took it once.
So the task would be to make the coastal road less preferable then the marches road for an army.
I suggest to have a seamless integration of the marches into the sea at the west end side (south of seagard, west of sevenstreams), and thus make the coastal road maybe dependable on the tides. A nice inspiration for this can be the wadden sea.
But maybe you lot have better ideas.