I'm pretty sure there are some coins, shells, flowers and fish not done yet but I did all the main stuff unless the fisherman gives something special for all the fish
Another thing I am unaure about is the photo. We never get it right?
You can destroy it - I also destroyed it, accidentally. If you find it in your inventory, then choose to inspect it, Claire notices it's actually a gold coin attached to string (or something), and you can choose to take it apart (destroying the medal and giving you 1 coin) or keep it. I wish I hadn't destroyed it, but maybe you won't :D