As for the colors, and this is not a cheap shot at the CC3 crowd, just a gripe I've always had about some maps, they could use a little more muting. The colors are reminicent of CC3 style maps where everything is in Technicolor.
I use CS3 and Illustrator to do my maps, so I know it is no easy task if you are not familiar with all the options and tools. I say keep it up and learning the various aspects and filters. Your already on the right track, now it's just a matter of refining the subtlety of color pallets and playing with the settings so everything starts to look like it is part of the scenery.
One way to tackle the color problem is develop a file that is nothing more than a color pallete. As you find combinations that work, just paint small swatches of them and then label how you used them and with what brush. This leads to consistency. Then when you have a good deal of them, make a custom swatch set in PS that you can load up everytime you get the mapping bug.