Using rescue disc image

When restoring the original install with the rescue disc provided by DS, what is restored exactly? My specific concerns relate to the os drive and storage drive data.

1) if the computer came originally comfigured with the os drive in raid and I wanted to, let's say, change to 2 stand alone drives instead; could I put both drives in achi mode and use the restore disc on just one of the drives or will the restore disc restore the original raid configuration. Sorry if the question is ignorant but I guess I'm wondering if the restore image is purely the os clean install or if it also sets bios settings? Is any formatting (full or otherwise) done or is it simply an erase and re-writing of saved image type function?

2) in a similar vein does performing a restore from the rescue disc make any changes to the storage drive data (assuming one is present or has been added since the original rescue disc was made) or is the os drive the only one effected?

As always thanks to everyone who takes the time to educate the less initiated among us.