My intention indeed is to add some bits and peases to make it more realistic. The tricky part is to add the details without compromising the high level look.
The aim for all terrain textures is to make them look a lot like hand drawn.

Some of the roads are so narrow that Photoshop doesn't create proper shadows etc to the surrounding terrains. I will have to manually fix them and make photoshop think that thy are actually wider. I have tried and it works, but I haven't done it to the map yet.
And as suggested I will add some ice to the water and some sandy beaches as well.

The mountains...I love them and I hate them. Those are actually taken from Google earth (most of them from Euripean Alps) and then I used "cutout" filter to make them look like hand drawn. Next step was to add "emboss" and "texture" layer properties to get some parts to come out from the mountain surface. And then lot of manual correction to fit it into the lanscape. The thing I hate is that when using real mountains as a base I couldn't make them go just the way I wanted, but I had to stick with the ones I was able to pull out.

The lightest yellow is a plain grassland, not desert. I'm not fully satisfied with the texture though...

And not to forget, thanks all for comments and ideas...