Are both centrifugal force and Coriolis force really fully explained by what is called "frame dragging" in GR? And if that is correct, does this concept "frame dragging" solve the problem of considering the motion of an observer on a rotating disc is in an absolute motion state? And is it the case in linear acceleration? What I know is that the equivalence principle was introduced by Einstein to solve the problem of absolute motion in accelerated frames, is the equivalence principle applied on rotating frames, as accelerated frames? Or not? And if not, why?
Are both centrifugal force and Coriolis force really fully explained by what is called "frame dragging" in GR?
Centrifugal and coriolis effects are explained by special relativity, without needing to introduce GR. They're explained the same way they are in Newtonian mechanics, since Newtonian mechanics is the low-velocity limit of SR.
Frame dragging is a different and normally much weaker effect.
Einstein's pop-sci description of GR in terms of gneralizing from inertial frames to noninertial frames is not how any relativist would describe it today.