back on the yoke slightly...as doing so, increasing thrust slightly
I never flew the 727 but have fair amount on the various 737. Interesting about your point above of increasing the thrust slightly during the flare.
I have seen this technique used in the 737 and also in the simulator. When asked the pilots concerned their technical reason for giving a "burst" of throttle at the flare, people couldn't explain why - although I realised after watching many of these power bursts it was often a reflex action - despite their aircraft was perfectly positioned in the flare for a good landing. In other words it seemed a good idea at the time!
In the simulator I found it difficult to convince some 737 pilots that there was simply no point in this burst of thrust as all it did was cause the aircraft to sometimes balloon slightly and land deeper into the runway. In some pilots this habit was so ingrained one could not break it rather like the jerk that occurs involuntarily when you hit your knee lightly.