1 - It is unoptimized
2 - It requires .gif support to be compiled into GD, which you are not going to have unless you do it yourself.
3 - It it still creating thumbnails on the fly as I have not had the time to modify the script to create thumbnails at the time of post.
4 - I already told you that I wasn't releasing it so why are you still asking
I could possibly in the future but I have too many things to work on right now that I can't bother with gallery.php right now.