What is the difference between a future lifetime and a past life or current life future extension? Are these really all the same except as having recognition of their sequencing in commencing from a particular preceding lifetime?

These are not equivalent. The future life extensions are, in effect, a future life in the making and represent a projection of probabilities that things will proceed as seen in whatever might be viewed taking shape within the akashic records as significant karmic events. In a sense, it is showing the potential for harm stemming from all that has happened already and, as such, it is a true reworking and repurposing of energies that is already gaining strength and being added to as a future event potential. This is the way energies converge and find like energies, and serves to bring the players into proximity who are needed to manifest the karmic destiny arising from prior life experiencing. This does not happen in a vacuum, as from a team of scriptwriters and a director to hire the players, and teach them the roles, and assign them their tasks, and so forth. It is all orchestrated energetically, and this is the manner of orchestration by karma, to create a future projection first that becomes greater or lesser in likelihood as things change in the prior lifetime creating the projection, so it is the case that things that go wrong not only affect the present moment but create a future projection of possibilities as well. And the more it fits the mold of other things that have happened, the more it will resemble a composite of prior doings and become more and more likely to burst on the scene in a future lifetime, and being within the future projection makes this a very great likelihood to happen if the energies are intense and represent something that causes a great imbalance needing correction. When a future life in actuality takes place, it is because there is a certain intensity and level of importance to the temporary future life projection and then it becomes a destiny, in fact, by being launched as a new lifetime done in parallel, but because it is flowing in actuality as a consequence of prior experiencing, it is called a future life for that reason. It may well overlap the current lifetime and thereby be of even greater importance to current doings. So the major distinction here is a difference of degree in which in terms of the likelihood of events taking place and continuing forward as such without a reworking, or a fading from the scene to end gradually, or even abruptly, without a conclusion. In other words, a future life extension predisposes the emergence of the individual in a future setting, and time, and place, and family, but it can simply end if there is a breach in the sequence of events giving it a launching and maintaining its energies by receiving healing for those things that were taking place in the past life, or current life, giving rise to the future extension in the first place. So the future life extension is provisional and can end when its usefulness is overridden by healing of prior energies causing the projection into a future existence. The fact it is a potential makes it more malleable and more fragile, so it can simply disappear. It remains in the akashic records up to the point it was in progress and will register all trauma along the way, so it is not without consequence, it is simply then a matter of length of existence and the total impact on things as far as its overall significance is concerned. When the future life in actuality is launched, it is because the prior projections have coalesced sufficiently in intensity and organization to make it a permanent level enterprise by all participating. And then things will play out over the course of a full lifetime of experience and will not come and go, and vary, and be evanescent if there is a prior event changing the projected energies. The future life per se is a life of its own and will be independent of anything that happens in the other time domains, other than it will be influencing and be influenced, in turn, by their energies, but has sufficient level of energy and autonomy on its own to persist and play out. It will be influenced but not negated or brought to a sudden end by anything that might happen elsewhere.