Changing the profile location in Firefox and SeaMonkey

Not a problem ... just plug it into a USB port. Although, depending on how old the laptop is, it may support only USB 1.0 (or 1.1), and any file transfer will be quite slow.

My pleasure. Happy Holidays!

It stores FF's basic configuration ... how FF looks. Following the old Chinese adage that one picture (two, in this case) is worth a thousand words, see the screenshot. There are lots of extra vertical separators using my localstore file because I didn't copy over any extensions, whose icons would normally appear between them. I didn't remove them for the screenshot because I didn't think of it in time. It's easy enough to do, though, using FF's "Customize" feature.

Yes.