What do you mean by the "Relocate Function"? if you have large collections of images and music on your "C" drive then you should back them up on another hard drive anyway! If you move them to another HD whether internal or external you can easily create locations in the Libraries folder and these locations can be shared as normal.
Not sure what you mean by "Can I follow the same plan with the to-be-installed Win 7 on SSD?" A SSD by its nature will be much smaller than a modern "normal" HD so you should only use the SSD for the OS and your programs. I would not recommend storing any data on it. Keep as much free space as possible. A 120Gb SSD will be big enough for Windows 7 and a good few Programs. If you have lots of games installed you might think of a bigger and more expensive, SSD on install some of the games onto a second internal HD. I must update my system specs as I have a 180GB SSD and I don't even store my Snippet screenshots on it.