Intercept login check for comments

I am trying to write a plugin that will bypass WordPress’ checks to see if a user is logged in or has name and email set if the user is already authenticated via another means. (in this case, OpenId) I know that I can always hack the core files, but I was wondering if there was a way to do this just using actions/filters. I hope to be able to release my code when I am done and asking everybody to manually edit wp-comments-post.php seems like a bit much.

I would also like to be able to allow the user to edit the comment if their OpenId identity matches the website url provided when the comment was originally posted.

Any tips would be greatly appreciated.