Answers to 1 and 2 anyway
1.) No, as long as the receiving HD is large enough to accept an image file.
This is where it pays to have kept the operating system separate from the data which I hope you back up often. The image file is then small enough not to take forever to make or restore.
2.)The image is of a working system, warts key numbers and all. It (the image is already activated/registered and complete)