I'm writing my own PHP framework with typehandler, image methods, paypal, sql etc etc.. But can I prevent other scripts from initialize those subclasses? Only Framework.php should be able to be initialized.

The only solution I can think of is extend and abstract:

Image is abstract
SQL is abstract
Framework extends Image and SQL

but that would require a lot classes to be extended everytime you load Framework.

Can you be a bit more clear about what you are trying to do?

PHP does not support multiple inheritance of abstract classes so having framework extend image and sql isn't even possible. A class can implement multiple interfaces however.