To answer question No. 2, such technique would reduce engine wear only in that it would involve applying reverse thrust later in the landing roll and for a shorter time (assuming reverse thrust is disengaged always at the same speed, which is normally in the region of 60 kt), something that the pilot in the video might not have taken full advantage of.
Whether landing a 747 that way is a good idea, is a different matter, and Bianfable's answer quoting from the FCTM provides some indications.
Bonus info: regardless of the wisdom of doing wheelies on landing, the idea of delaying as much as possible the application of wheel brakes and reverse thrust (while dissipating as much kinetic energy as possible through 'free' aerodynamic drag) is sound.
The A380, for example, was the first to introduce the Brake To Vacate concept for the autobrake.
Unlike the ordinary autobrake settings LO, 2, 3, HI (which are still available and engage wheel braking at constant decelerations as soon as the landing gear is on the ground and the spoilers deployed), BTV starts applying brake pressure just in time to bring the aircraft to taxiing speed when it reaches the selected runway turn-off, not before.