i agree with michelswiss for the photo system (it's need to be simplified)

for the profile menu (profile, friends,photos,videos),i suggest that if the content don't exist the link will not be displayed (like facebook), for exmaple : if a member don't have a video or event the link will not visible, because with application installed this menu will be overload (surchargé)

for the blog, it's necessary to let only the categories that was created by the member in his blog