Change behaviour of Publish button in PW Admin

[Mr. NiceGuy]

I'm building a knowledge base profile.  

What I'm currently on: A user with the role guesteditor gets logged in and is allowed to add a page with the parent "drafts". 

After the guesteditor saves his page I want to notify an admin who then moves the new page if any good to its destination. 

So far so good.  

My question now is if I can change the names and behaviour of the Publish and Save+Keep Unpublish Button to a Single "Request Permission from Admin" Button. After the button is clicked I would like to send an email to admin, save a value to the same page that the permission request was sent and display instead of the button  a message like "permission requested on xx.xx.2015"  

How do I do this? 

I'm planning to write an autoload module like described here https://processwire.com/talk/topic/2331-doing-additional-logic-after-saving-a-new-page/ to populate some fields  through the URL that the guesteditor clicks to add a new page. 

Are there similar methods to do the thing described above?

Thanks!

[LostKobrakai]

You can use hooks to modify the return value of ProcessPageEdit::buildForm, which generates the button. This will help you get started with the form generating api: https://processwire.com/talk/topic/2089-create-simple-forms-using-api/.