If you would've asked on your actual account instead of creating a sockpuppet, someone could've linked you to the pages of the posts that were hidden (you still wouldn't be able to see the image on those pages, but you would at least be able to use the favorite/unfavorite button).
For the second question: Deleting an account automatically changes the name on all the changes and comments, etc., to "User ######" (with the number filled in). I'm pretty sure it also automatically unfavorites all favorites, so if you're going to be getting rid of the account anyway, you wouldn't need to go through that step manually.