Mod Manager ?
 

Does the game support any kind of mod management? How to make a mod without modifying core files? Should I make another "pak" file, mod folder or something else?

Well, you can create another game copy simple making copy and paste, because there's not registry problem. I think will work also the tool JSGME, which permits to manage a mod directory in the games http://www.users.on.net/~jscones/sof...cts-jsgme.html