Okay, after toying around with this whole thing, I've come up with some methods for using Photoshop Elements 2 to emulate your style as much as possible. I still have not successfully tested it on the Earthlike planet or Star types yet, but it works pretty well for the Rocky Planet/Moon type.
Selecting Color Range is not supported in Elements 2. To emulate that effect, I created a Threshold layer above the Hills and Mountain layers.
Mountain Layer
Click on the Threshold layer. Use the Magic Wand tool at a Threshold of about 175. You can play with that number as you like. Use the Magic Wand tool to select the white portions in the Threshold layer. Click over to the Mountains layer and hit Delete. Then Deselect (CTRL+D or through the menu). Drag the Threshold layer to the trash.
Hills Layer
Same basic concepts as Mountain Layer. All I did was change the Threshold setting on the Magic Wand to about 125.
Since Color Overlays are also not supported, the closest I could come was to create a Solid Color layer over each; Land, Hills, and Mountains. I used the brown color you described in your tutorial. I then set the Layer Mode to Overlay and then linked each set and merged the linked layers. That is a separate action for the Mountain, Hills and Land layers.
Layer Effects are present but very limited. I was not able to set any options for them and so the shadows on the mountains layer turned the "mountains" into craters and canyons.
I can get into more detail if anybody needs. Mostly I am just describing how to alter your tutorial for the purpose of using Elements 2. Not even sure how many people even use it. Looking on the web, Elements 3 (and presumably later) have Select Color Range built in.
I've attached an image of a moon that I built entirely in Elements 2. I could have easily attached an atmosphere, but I wanted to test the basic concepts first. Besides, I need a good moon image for another project. I think you will see that it is closer in concept to your examples than my first effort.
Again, thanks for the wonderful tutorial. It has been very engaging trying to adapt it to the tools that I have. Later today I am going to try the Earthlike planet and see where I can get with it.