post-levels plugin: way to hide comments made to private posts?

I’m using the post levels plugin to make private posts visible to the administrators on a (WordPress 2.0) blog. Comments to these private posts are, however, visible to ‘authors’ on the Manage > Comments Page. This makes it impossible for administrators to privately respond to these posts (short of writing a new post each time, resorting to email, etc.). Is there any way to prevent blog authors from being able to view the comments on private posts? This problem also occurs with blogs that don’t use the post levels plugin (comments on private posts are visible to other blog authors), but it is more severe when there are multiple people who might comment on a private post.

More specifically, is there any way to:
– Allow blog users to write and publish posts but not manage comments (my reading of http://codex.wordpress.org/Roles_and_Capabilities suggests that both of these abilities fall under the edit_posts capability)?
– From a comment_text or get_comment_text filter, determine whether the comment’s post is private, and get the level of the current user? This would allow me to hide the comment’s text from unauthorized user – though they would still still the author and date of the comment.

Or is there another option (besides hacking at the WordPress source)?

Thanks for any suggestions you can offer.