That's coming along nicely. Its great that you're doing your own thing when you cant follow some of the terms etc. As you say, it helps as part of developing your style as you do things that suits or gets result you are happy with.
It almost looks like a cross between styles , with soft and hard gradients together. The hard pixel edge of the coastline might be nice blurred a tiny bit to soften it - But that might be just me.
I usually have a black and white version for land and water, then I can select those areas and use Filters>Blur>Guassian Blur . You do have that hard black pixel coast edge which you could use to help select the land - if you have your work over layers you can then have a mask to select land or sea. the bits you have smudged in the land are looking OK though.I cannot smudge or blur my land into looking good
I like the colour palette and it's also an interesting region overall. I look forward to seeing it develop.
thanks for showing it to us!