Hey man, I'm also new to this forum
I like the map, its nice and comfy, but the only thing I would tell you is that the coastlines seem to straight, I always try to make them very pointy and changing through space a lot. In my opinion it gives a bigger sense of realism to the map, but its nice anyway man.
I tried CC3 but i had some problems with it so I went with GIMP, really happy with it, though CC3 seemed quite nice looking.
For the coasts, I always remember a guy who told me that coasts are like fractals, like they're always irregular, and the more you zoom in, the more irregular they are haha
Cheers mate.