Varnish looks like a step in the right direction and possibly useful in peripheral activities.

Regarding rsync/git/torrent to inner hosts this would almost certainly not be possible or even desirable with the resources available. The catalyst application provides searching, labeling and vast ammounts of meta data for the files, the sum total of which goes past the 800gb mark at last count (mainly proprietary format binaries) and then throws out a link to direct download. The value of the system is in the cat based meta data which needs central user/automated administration and update since it's practically the fulcrum of the entire workflow.