...because for some bizarre reason SMF won't let one turn signatures off entirely. Thus they are limited to one character. The idea was that the content is king - no need for HUEG fields of text or massive banners to distract people.
Attachment are off for security reasons, and probably for bandwidth reasons as well. Have always been. You can always host elsewhere, if you need.
Pictures? You mean avatars? They are not working? ...I guess the upgrade might have broken them.