I have been able to use Moodle on my eDGe without any problems. There are a couple of other secure campus sites (internal wiki, etc.) that I can access but can't load or download files using the built in browser but I can if I use Opera.

As far as textbooks, I've found that many of the etextbooks you have printing rights (check the details before you buy). I use a mac so I print to a pdf file and transfer it to my eDGe. It's not a perfect substitute but it works (and is compliant with fair use standards) if you can't get a pdf or epub version from the publisher.