There are many different acronyms of ETOPS. Some acronyms of ETOPS are, Extended Twin Engine Operations, Extended Twin Engine Over Water, or Engine Turning or Passenger Swimming.

Certain variants can fly the longer, transcontinental routing, provided that payload is low. This is often used by all-premium class airlines flying few passengers, such as some Privatair flights. To cross oceans, the aircraft must be ETOPS certified, along with the operating carrier.

Quite well. Modern aircraft are configured to fly and land on one engine

Well, from FCOM VOL 2, Special Ops, Extended Range Operations section gives you 130kg/hr or 287lb/hr. That is for the APU with APU GEN ON and APU BLEED OFF. But that for the ETOPS critical fuel calculation. That should be it right? Im not very sure, as im looking for the same thing.

Environmental Threat and Opportunity Profile (ETOP).