The B777 was designed to be operated by two qualified, experienced, well trained and current pilots in the two front seats. Pilots following SOPs (and not modifying them with following a bit of hangar talk or "it seemed a good idea at the time your Honour quick fix.) Pilots watching, one watching the aeroplane, the other watching the PF, the TMA and the various flight path parameter indications. If the preceding conditions are not met then there may well be tears. Little has changed in aviation.
It is true that to deeply understand the pitch, speed and thrust systems and modes takes a bit of delving. Hardly tough duty. Your airline SOPs as practiced in the sim and LOE will probably cover the bases. Nevertheless it is true that the B777 Systems FCOM is a bit thin. But a bit of Sherlock Holmes stuff can unlock a lot of secrets. Your airline will probably have an in-house Boeing rep with all the deeper books. None of the "secrets" wiill be life-changing but will add a bit of gloss to your life as a pilot and avoid splinters in the bum. Good airmanship does rest on a bit of effort to build knowledge. How many people really did understand, (or remember) as the Emirates crew found out sadly in DBX on a rejected landing, that the A/T ceases to be active at 2 ft RA. Otherwise you could never land. Problem is if you reject the landing below 2 ft then pressing the TOGA buttons will not make the thrust levers active, You actually need, as you should have been trained and every pilot back to the Wright Brothers was trained, to push the bloody thrust levers forward as you announce "Going Around". Or if you are, probably unwisely, going to cancel a rejected landing after initiation, then remember that using the thrust levers forward disarms the auto-spoiler and auto brakes. Think QF1 at BKK. Knowledge is key.
(pause to think back to the days when you practically had to be able to build an aeroplane to get a type rating.)
Having said all of the above there are probably a few things the manufacturer could put in place to avoid traps. Just as not that many years ago the ILS arm/capture logic functions were changed to prevent G/S capture before LOC capture. Thumbs up. And the entry fields in the FMS were altered to prevent entry of ZFW in the TOW line. Thumbs up. Though its been a while since an aging Sherm had the privilege of commanding a B777 I think a good case could be mounted for preventing the use of FLCH below, as 3,000 ft on approach. Years back I recall an incident in Milan where a 744 crew, a bit high, selected FLCH on a NPA after crossing the FAF, Not a good idea.
The B777 is a wonderful aeroplane. And it will pretty much always tell you exactly what it's doing or soon will do. But just as no-one should ignore smoke in a dynamite factory, or a dying canary in a coal mine, no-one should ignore it when a sophisticated MCP and Thrust Mode Annunicator tells you exactly what's happening or will soon happen. And most important of all, if you are in any doubt, go back up there further into the sky where it's safe.