Once a Channel is published with Direct Publisher and since there is no new package to upload when a change is needed, if I make a change to the channel, Feed location or whatever, does it have to go through the approval process again? I was thinking not since the main look, overhang specs, etc have already been approved due to the initial channel publish process.
You're correct — once a Direct Publisher channel is published, you can change its contents at any time by reconfiguring your feed. You'll only need to resubmit the channel if you change the channel information or brand assets.
Note that the changes will not appear immediately. Your feed is re-ingested about four times a day, so it may take several hours before you see the edits. You can, however, create a separate "clone" private channel to view edits immediately