moving the Jin like drawing silk,
rooted in the feet, developed by the legs, guided by the waist, and showing up in the hands and fingers
loosening the waist,
sinking the Qi to the Dantian,
sticking Qi to the back,
emitting Jin like shooting an arrow.
loosening the abdomen
distinguishing full and empty.
My understanding of fa-jing follows these "maxims" particularly looseing the waist and abdomen.
All fajing should follow the same principles regardless of how and when it is done.
What i mean by letting the explosion carry the body is imagine the strike hitting its target. If the waist is completely loose after the strike, it will snap back in the opposite direction and back again repeatedly until all the energy exerted is dissipated, a bit like a ball bouncing.
If you were to physically turn the body back and forth rather than "allowing the explosion to carry the body" then in my opinion, your waist would not be loose.
I would turn my waist on the initial strike to guide the fa-jing and then let the shake/explosion take over.
In principle, with each turn of the shake you could strike again with the opposite side of your body so left-right-left etc potentially creating continiously flowing strikes.
p.s. if you are interented in having a look at what we do and how we do it up close, i understand Eli (Erle's son) is holding a workshop in the states next month. For when, where and how much you'd have to contact him via his website.
What you are refering to is IMO ''Whole body Jin'' or using ''shen fa'' to utilized the spiral energy from ground, thru feet, leg, waist and out from hand. In this type of fajin, both the hand or hands must arrive together with the feet, while maintaining body structure at all time. The residue 'oscillation' energy from the 1st strike will be used to generate the momentum of the next strike or continuous flowing strikes. Most if not all IMA uses this method to hit together with stomping. This can be found in the Chen style and some old form of Yang. Maybe you are learning those ?
On Erle fajin using the sound of Heng or Hai and ''lose himself'' when doing it. We are training something similar but at the most we 'hiss'. Very small movement in the arms, expressing it out from our fingers, with very slight body movement. Hardly as we improved. We do not use the ''lose oneself''. What we do or not do, is (not to)think of the opponent.
For the Peng arm, I learned both the Yang Jun and your style of Peng energy. We also do not let the arm collapsed into the abdomen. If it does that means our structure integrity is down and opened to attack. In keeping this structure, we have to ''hold in the chest and rounded our back'' as well as the other maxims etc. It was while doing these PH, I experienced the feeling of //Advancing, he finds the distance longer, Retreating, the distance seems exasperatingly short//
About your Qte// Yes we use force
but never resist // UQte. To used force or Li is also contrary to the taichi principles. Unless your force meant using sufficient Li to hold up your structure, then I am in agreenment.
As for the Explosive FaJin, so far you(Pete) have not given a clear picture of how it ''feel'' like when one get hit by one. I always asked this Question everytime I come across fajin demos at various workshops. Maybe you can elaborated in your next post. Anyway in the Explosive fajin that we train, when hit, one feel like he is being hit by an electric charge and jump up or goes backward and jumping at the same time, depending on the ''intent'' of the firing partner. In the old days, the Master like Yang LC, would train fajin very aggressively causing damages ( so that they can confirm if it works I supposed) and therefore not many dare to be the partner. I read these in some write-ups of how they train in the old days. But in this era, the teacher only use 10-15% of their internal energy when giving demo or during training. Because of this ''safety'', most view these demos as fake and also weak as they don't seem to inflict much damage.
To understand where this Jin come from, I like to quote what IMO a very clear explanation in relation to Qi and Jin. // Jin is the manifestation of Qi in Combat form.// It comes from the Dantian. The ''descriptive'' feeling that I have from the 13th Taichi Postures is // Direct the Qi like threading the 'nine bend pearls', by flowing continuously, like tempered steel, it reaches everywhere, overcoming all solid defences.//
Anyway, I hope you find the above useful.