You are welcome. As for your next two questions:
1) Yes, you can user the "mv" command from the shell's command line to "move" files from one directory to the other "en masse". As you mentioned you are going to be moving 10GB of files, make sure and preface the "mv" command with the "nice" command, so that the process will not run afoul of the DH "prockiller" daemon, which monitors the system for programs running too long or consuming too much system resources, and kills such processes when it finds them. There is also the "cp" command for copying files. "mv" differs from "cp" in that "cp" only copies the files (leaving the original file untouched) while "mv" effectively "copies" and then "erases" the original files (leaving no copies of the original files).
Actually, the most general way to "rename" a file in Unix is to "mv" fileA to fileB, effectively "renaming" it, but there other tools available in some distributions (particularly linux) for doing "enhanced" renaming.
2) DH's version of Debian Linux has a "rename" command (actually a perl script), which allows mass re-naming of files using perl-style regular expressions. The program itself is easy enough to use, but you may need to do some research/learning in order to produce an appropriate regular expression to address your particular situation and the filenames you are using. Again, depending upon how many actual filenames you have to manipulate, make sure to "nice" the "rename", as a courtesy to other users and to avoid your process getting killed.
The use of all these tools is described in detail, and there are many tutorials on their use, in many places on the web - a few carefully run Google searches should provide you with instructions and/or tutorials suitable for your needs and present level of knowledge.