1. Not available yet.
2. Anything should work. Look at a Pegasos guide for specifics.
3.
http://www.pegasosppc.com4. Not yet. I think Vesalia sells partial bundles (board, disk, graphics card).
5. The board comes with an AGP adaptor. The Radeon 9250 that shipped with Pegasos ODWs has been seen using that slot successfully.
6. No way to increase the RAM is yet known. There are pins for 2 more RAM chips on the underside of the board, but there's probably a bit more to do than just soldering them in place.
7. The inability to easily add any kind of internal CD drive is a point against it, but the Efika will probably be the cheapest of the Amiga-like PPC options.