Customizing RT's Screens

Three questions:

  1. How can I customize the “Jumbo” (ModifyAll.html) screen to only include the sections I want (basics and update ticket only)?

  2. How can I modify the Update Ticket section of the “Jumbo” screen so that the update type is always defaulted to Reply to Requestors?

  3. How do I make this new screen be the default screen when a user clicks on a ticket / takes a ticket?