How can I hide the msgBox and the panes for a given room which serves as an intro to the game with no interaction from the player?

You can show and hide the panes using:

• JS.panesVisible (false)
  and
• JS.panesVisible (true)

This both disables the panes and adjusts the screen size to make them fit.

In looking at an old posting I stumbled upon the code to hide and show the msgBox:
request (Hide, "Command") and request (Show, "Command").