Why do I have to configure an include_path when installing Zend Framework instead of just manually including? I've never done this before and can't really see the point, also I've spent some time trying to figure this out with no luck hence why I ask.
Actually I add Zend framework to the include path to be able to use Zend tool.
If you want to create a project structure and add controllers or models or even scripts using Zend Tool you will have to have Zend framework added to your include path.
Another reason you may want to ship your project without the library itself so that the end user doesn't update the framework version himself and break your code.
Also if you are working on different project at a time you may want to keep only one version of the framework shared between different projects. This is handy when you need to update your version of the framework without going through all projects every time.