A simple feature: Implement a block list specifically for the Photo Gallery
Thoughts: It'd be based off your current address book block list, OR, a brand new section in your settings and or Photo Album settings (lots of options and ideas) to block a specific set of users from commenting on your gallery instead of completely making it private.
Reason: The picture will remain public, but you'll be able to keep out those specific users that comment on all of your photos with negativity instead of needing to re-delete their posts continuously.
What's your opinion?