Does the git-clone command have resume capability? If it gets interrupted while I'm downloading a large repository will it resume if I give the same command again?
No, cloning cannot be resumed, if it's interrupted you'd need to start over. If you suspect that there's a good chance that your clone may be interrupted, look for a git bundle that you can download using a protocol that can be resumed. You could then use that to create the initial clone, and use the actual repository to keep up to date.