Shakycow
I Love YTtalk
You can flag multiple videos on a channel with a single report (you still have to fetch the URLs though).
Flag 5-6 entirely reuploaded videos per channel and they should be removed in a week or so (from my experience).
The problem with batch reporting videos is that the report only counts as 1 copyright strike.
Since a channel is terminated after 3 copyright strikes, it's often worth the extra hassle to issue the each of the DMCA's independently. Send in a DMCA report, wait until you receive confirmation that the video was removed, file another, and so on.