Don't worry about asking too many questions, Tako. There are never too many questions.

And that was my main answer.

I'm sorry - I did search for the 'official Game of Thrones map' and various other combinations of those words, but I didn't find anything that was some kind of bone fide official map to get an idea of what you want. Instead I got all kinds of very different variations of the same land masses done in hundreds of different styles. So maybe if you could provide a link to the one you regard as being the definitive map I might have a better idea of what you are looking for.

I suggest a hyperlink to the ideal map because every one of these maps are copyright to the artist and should not be reposted here on the forum without their permission.

To create a new sheet just hit the Add... button on the left of the sheet list in the Sheets and Effects dialog. Then move it up or down the list to the best position.

To copy the sheet effects across from the existing LAND FEATURES sheet, pick the existing sheet and select the effects in the right panel, then hit the Copy button to the right of that panel. Select the new sheet and hit the Paste button.

You can move polygons or symbols to other sheets a number of different ways. I use the Change Properties tool as the fastest way, but you can also use Move to Sheet in the right click menu of either the Display Speed Settings button, or the Sheets and Effects button.

When in metric maps scale to the appropriate metric unit, which is km in overland and m in both city and dungeon

And in imperial maps scale to the appropriate imperial unit, which is miles in overland and feet in city and dungeon.

That is correct. It doesn't matter if it's the wrong value.

I would give them a default scale in import for the reasons Remy explained. If there's no scale they don't get smaller when you zoom out or larger when you zoom in. They just stay the same size, which isn't the size you will see when the map is exported.

Giving them a scale stabilises the situation so the tile actually looks the way it is no matter how zoomed in or out you are, and no matter how large or small you export your map.