1) Browsing the filesystem. You could, i.e., install mc (midnight commander), and this will allow you browsing the whole filesysthem from a terminal window. GUI apps like the enclosed file manager will only show your home directory and the contents of MMC cards... this in order to stop you making something dangerous to your operating system.
But, what's exactly your aim? Are there problems with GPE? Please specify.
V2) Yes you can use your own image as a background. I can't give you the exact menu commands in English because my interface is in Italian, but on the upper left there should be something like a "Start" menu; under that, there should be something like "Tools", and finally something like "set background image". Most likely, your images will be in /home/user/Mydocs/.images - this can be reached also with gui apps.
3) I respect your opinions, but feel that under-paid chinese and mexican people should have a chance to work for their families.