The transponder location, usage and FMS details are available for $90 US in a "BOEING Officially Licensed Product." Run the PMDG 777 sim package in FSX or Prepar3D on a $2000 PC and you have most of the answers. The PMDG sim will provide way more detail than has been conveyed on Television.
PMDG Simulations - this link is for the 777 sim package - take a quick look at the details
There are also multiple manuals and study guides published on real paper and on the internet that provide very specific guidance to want-to-be 777 pilots.
Talking Heads (knowledgeable or not) are not revealing any secrets - at least based on the very technical discussions in the very PUBLIC PMDG and FSX user groups.