Blargh...

I now have it porting the correct information into the correct columns in the columns table. There are just two problems.

1. It is putting null information in as comments for posts that don't have comments.
2. It still isn't passing the post ID to comment_post_ID, so the comments are still floating in limbo instead of being associated with posts.

I'm trying to fix the second problem first, because it's the most serious. I think I can solve the first problem with a workaround that already exists for deleting empty posts. Besides, that's not really as big an issue to me as making the comments actually appear!