Over 23.000 hours on different types, including 4 engine 747, I only look at engine parameters to make sure they are about the same on all engines. Except initial power set in case of unreliable airspeed. Then it's the same story - set power whatever you need to maintain the speed and change the speed trend. I don't know what is practical use of knowing the numbers.
And I love to fly manually and use manual thrust.
I also cannot recall my crew mates mentioning numbers and freguently looking at engine parameters.
Regarding unreliable airspeed. Pretty much the same technic. I mean on my present Airbus with BUSS. Just keep the speed in the green. With the same thrust control habbits. Have no idea what is EPA or N1 in the process. Once again - except initial pitch/attitude set up. But it in turn happens only for initial level off until you figure out what's going on.
Just add or reduce power as much as you need. Regardless of numbers on displays. Easy life
