Any way to inherit methods from both my plugin class and WP_List_Class?

This is a common design pattern, and I would have solved it in the same way you did. Let My_WP_List_Class extend WP_List_Class, and pass a “configuration” object to it. You could even make the relation more explicit by defining an interface your configuration object must adhere to:

interface My_WP_List_Configuration
{
    public function get_name();
    public function get_admin_page_uri();
    // ...
}

class WPSE10402_Plugin extends Wyrfel_Plugin implements My_WP_List_Configuration
{
    public function get_name()
    {
        return $this->_name;
    }

    public function get_admin_page_uri()
    {
         // ...
    }
}

I don’t see much difference with the current way of using actions to hook your functionality into. Yes, your code is now structured in a class instead of in a list of functions, but that is the only difference, no?