NOTE: In consequence of some answers of users due to whom part of the issues become clarified, I do from time to time MODIFICATIONS in this question stressing the remaining questions.
Shan Gao, the author of the book
Article The Meaning of the Wave Function: In Search of the Ontology ...
proposed a new interpretation for the QM: a substructurea of QM consisting in a moving particle. But instead of moving continuously, as in Bohm's mechanics, or as in the trajectories of all forms considered by Feynman in his path-integral theory, Gao's particle performs a random, discontinuous motion (RDM) - see section 6.3.2 and 6.3.3 in his book. In short, gao's particle jumps all the time from a position to another
"consider an electron in a superposition of two energy eigenstates in two boxes. In this case, even if the electron can move with infinite velocity, it cannot continuously move from one box to another due to the restriction of box walls. Therefore, any sort of continuous motion cannot generate the required charge distribution. . . .
I conclude that the ergodic motion of a particle cannot be continuous. . . .
. . .
a particle undergoing discontinuous motion can . . . “jump” from one region to another spatially separated region, whether there is an infinite potential wall between them or not.
. . . .
Furthermore, when the probability density that the particle appears in each position is equal to the modulus squared of its wave function there at every instant, the discontinuous motion will be ergodic and can generate the right charge distribution"
An important implication of the RDM interpretation is, as the author says, that the charge distribution of a single electron (for instance, in an atom) does not display self-interaction
"Visually speaking, the ergodic motion of a particle will form a particle “cloud” extending throughout space (during an infinitesimal time interval around a given instant), . . . . . . This picture . . . may explain . . . the non-existence of electrostatic self-interaction for the distribution.”
Part of the questions regarding this picture were already clarified by the posts of some users. The questions remained non-clarified are:
1) Is Gao's picture of a particle jumping from position to position, and visiting in this way all the volume occupied by the wave-function, fit for obtaining the Feynman path integral?
Feynman considered two points in tim and space (t1, r1) and (t2, r2). He also considered all the possible paths between these two points - the majority of the paths having crazy forms, though being continuous. The particle starting at (t1, r1) and traveling to (t2, r2), was supposed by Feynman to be totally non-classical - it was supposed to follow SIMULTANEOUSLY all the paths, not one path after another. This is was permitted him to do summation over the phases of the paths, and obtain the path integral.
The movement of Gao's particle is not only discontinuous and endowed with no phase, but it os also SERIAL, one point visited after another. What you think, if one would endow these discontinuous trajectories with phases, could we obtain Feynman's path integral despite the seriality of his particle's movement?
3) Gao author also says
"discontinuous motion has no problem of infinite velocity. The reason is that no classical velocity and acceleration can be defined for discontinuous motion, and energy and momentum will require new definitions and understandings as in quantum mechanics"
This statement seems to me in conflict with the QM, because the uncertainty principle says that if at a given time a particle has a definite position, the linear momentum (therefore also the velocity) would immediately become undetermined. QM doesn't say that the linear momentum does not exist.
Can somebody offer answer(s) to my questions/doubts?