IPad – use the iPad Camera Kit to move photos onto an SD card

The iPad Camera Connection Kit is simply a USB hardware interface. It performs no processing and can store raw as well as jpeg from a camera or SD cards.

The iOS photo app will show you the pictures it can, but of you have an exotic raw camera - it will simply hold the images unchanged to deliver to your computer rather than process or change any images.

No, not straight from the iPad. The Camera Roll is like a smart folder: it contains all items that were stored as pictures on the iPad from apps. You can't move pictures from there to another album, just like you can't move songs from the iTunes library to playlist.

However, if you import the pictures on your computer, then delete it from the iPad (you didn't specify your OS there, but assuming Mac OS X: with iPhoto, it simply asks you whether you'd like to do so after the import is over), syncing the pictures that were in the Camera Roll back onto the iPad will make them appear only in the albums you've configured on your computer, not in the Roll anymore (since they were not added from the iPad).