#4 really is key. Yes, you can do it on the Pocket eDGe, but the form print will be so small that you probably won't be able to read it (assuming these are PDF forms). The pan and zoom features for PDFs is very awkward and essentially unusable except for very occasional use.

With the current software, you'll need to do your annotations while zoomed out (you can zoom in to read, if the print is too small, but you'll need to zoom out to annotate) - at least that's my recommendation from my own usage. This will ensure the PDF is exported at full size and with the annotations in the correct locations. While you can annotate different pages at different zoom levels, the resulting exported PDF may have some annotations shifted due to zoom differences, and the page itself can be truncated at the borders (i.e., if zoomed in, the PDF will only show the pages as they show in the Reader). A lot of this awkwardness is due to the Adobe software that enTourage is using and which enTourage has limited opportunity to change/fix/improve. Future updates will hopefully improve this.

As for the PE, it does make a great companion device (I have both, each with their designated use).

Regarding marking up Word documents, you'd need to check the DataViz site for documentation on the Word To Go app in the Documents To Go suite. Only PDFs and EPUBs are displayable on the eInk side.