I just found these posts in the FAQ section and am wondering why they are here and why some have so few responses. It seems since they are FAQ they should have some fairly concise responses. At the risk of getting the "why are you responding to an old post" flame, ( I never understood why this bothers some people), I would like to add to this thread.
Re: beats. Yes, some intervals have multiple coincidental partials. You may be hearing other partials but only the coincidental partials (C.P.) beat.
Common multiple beating partials.
The P5 has the 1st C.P. an octave above the top note. The 2nd C.P. occurs two octaves above the top note.
When using F2 to tune A4 to the fork, there is a C.P. at A4 when playing F2Fork and F2A4. The 2nd C.P. occurs at A5.
Multiple C.P.'s can have different beat speeds, Therefore it is important to train the ear to seperate out the different beat speeds and focus on the target C.P.
Re: lever technique. This is a huge question but basically the two styles are Slow Pull and Impact/Impulse.
Some technicians swear that one is better than the other, but the fact that different technicians swear by different techniques means some don't use the others technique the same way, certainly not with the same result.
Both ways have their place. An understanding of forces, friction, elastic deformation, and the non-speaking length tension during, and after tuning, is imperitive if you want to be able to acheive stability on all different kinds of pianos.