I quite like the direction this map is taking. There are a few little things that stand out to me straight away though. I haven't read every post in the thread so I apologise in advance if I bring up anything that's been covered.
You have a lot of dead space in your image. Perhaps bump up the size of the legend, but not too much becaues you don't want to crowd the actual map. I can't determine any order to the continents in the key, so perhaps if you arranged them from shortest to longest it would help with the curved space you have to work with. Another option would be include some images in the background, but I think that would hurt the style you have going now.
I think that perhaps the map needs some very faint stroke/outline around it to seperate it from the background. A lot of your borders around the edge of the map don't go all the way to the edge, a stroke around the map would help give these borders an end.
The font on the map itself isn't really ideal. It's probably a bit too small to start with and it doesn't fit with the rest of the image at all.
The one way borders do the job, but they do need to be a little more obvious. Playing around with highlights, outlines and shadows should be able to give you some sort of satisfactory result.
Keep up the good work Bodmanbod.
