This happens if the fill style doesn't have a specified scale in the fill style dialog.

Just open the Fill style dialog (FS: in top right), go to the bitmap files tab, find your fill in the dropdown, enable the scaled checkbox and provide appropriate values for the scale. Some experimentation may be needed.

Once a fill is scaled, it should always fill the same area no matter the zoom or export level.

Great looking map.

Do note that while the image size in posts are limited, you can upload much larger images in your gallery if you want to show off a high-res version.

I am not sure what you mean by "terrain" in this context, but there is no way to embed images into a drawing, none of the official ProFantasy art is embedded either.

What is normally done is to either store external images in a subfolder in your CC3+ data directory, because you can then refer to it in the map using the relative @-indicator in the path. For your own custom artwork/images, you can also store it in the same directory as the map itself, and then use the map-relative identifier ($) in the image path to refer to these resources, that way, you can keep everything in the same folder and it will continue to work no matter how much you move it around, as long as you always move the entire folder with map and artwork together.

If they are just inserted images, you can use :CC2EDIT: on the red x to see and change the path. If they are symbols, you can do the same, but you need to open the symbol up for editing from the Symbol manager, you can't do it straight in the drawing.

Note that sometimes it is a bit hard to select them when trying to change them, especially since numeric edit is a single-pick tool. The thing to keep in mind here is that the edge isn't always exactly where it appears to be. The trick is usually to zoom out a bit, so the pick aperture becomes large compared to the edge.

You can also use the REPLACEIMAGENAMESDWG command to do mass replace. See this blog article for more information.

This is a very nice map.

I guess you are using it for a battle-map though? Personally, I am not too fond when everything lines up with the grid, but that is often a tradeoff when you make battle maps, since it makes things much clearer for combat purposes.