The following should work fine:

git diff -z --name-only commit1 commit2 | xargs -0 -IREPLACE rsync -aR REPLACE /home/changes/protected/

To explain further:

• The -z to with git diff --name-only means to output the list of files separated with NUL bytes instead of newlines, just in case your filenames have unusual characters in them.

• The -0 to xargs says to interpret standard input as a NUL-separated list of parameters.

• The -IREPLACE is needed since by default xargs would append the parameters to the end of the rsync command. Instead, that says to put them where the later REPLACE is. (That's a nice tip from this Server Fault answer.)

• The -a parameter to rsync means to preserve permissions, ownership, etc. if possible. The -R means to use the full relative path when creating the files in the destination.

Update: if you have an old version of xargs, you'll need to use the -i option instead of -I. (The former is deprecated in later versions of findutils.)

git diff --name-status [SHA1 [SHA2]]

is like --name-only, except you get a simple prefix telling you what happened to the file (modified, deleted, added...)

git log --name-status --oneline [SHA1..SHA2]

is similar, but commits are listed after the commit message, so you can see when a file was changed.

• if you're interested in just what happened to certain files/folders you can append -- <filename> [<filename>...] to the git log version.

• if you want to see what happened for a single commit, call it SHA1, then do
  git log --name-status --oneline [SHA1^..SHA1]

File status flags:

Line numbers as in number of changed lines or the actual line numbers containing the changes? If you want the number of changed lines, use git diff --stat. This gives you a display like this:

[me@somehost:~/newsite:master]> git diff --stat
 whatever/views/gallery.py |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

There is no option to get the line numbers of the changes themselves.