This is a very well written piece of work. Most of the arguments in the review are well established and, thus, I do not have any objection for the acceptance of this review.
The review is very well written. I have only two very minor suggestions:
(1) At the end of the Introduction: The terms "radial" and "transverse" could be clarified that they correspond to "parallel" and "perpendicular" to the magnetic field direction.
"... the radial component of the thermal velocity generally exceeds the transverse thermal velocities." This could be clarified. Is it because of the solar wind motion along the magnetic field?
Matematical formulation, Eq.1: define also G=Newton's gravitational constant.