Backhand smash tips

[longrange]

Yes, but this assume one stops right away.

No, any departure from that minimal trajectory means applying an additional force. Why necessarily "one stops right away"?

??? I don't see what circular arcs have to do with the return to ready.

Has nothing to do and not supposed to; it's not in the cited text.

I would not return the paddle to the ready position using circular arc. I would try to reduce the radius of motion to reduce the inertia.

You can disregard return to ready position, but everything else applies: you have to choose two points on a (roughly) sphere, swing between them along a circular arc hitting the ball in the middle of the trajectory so as to impart the momentum and angular momentum you want. Departure from this trajectory would mean additional force and will be useless and traumatic.

The initial FH stroke does more or less. I am sure it isn't constant because we must adapt to the situation.

No, FZD's backhand motion is an arc on the sphere centered in his elbow.

In any case, I don't see any substantive objections in your reply.