Regarding the A&P, I don't see much in the way of similarities between yogis. The A&P can include anything from "a strange dream that you don't even remember" to "bliss and ecstasy". That's not good enough.
Having had no experience of the A&P or with vipassana, you're hardly in a position to comment are you?
You'll only ever find the A&P discussed, and labelled as such, within the Mahasi Sayadaw "Progress of Insight" model, the majority of other mystical or magickal models, while perhaps containing phenomenologically similar phases such as the attainment of Tiphareth within the Kabbalistic models, don't tend to talk about it in the same terms you'll find used on here due to social, cultural and various other levels of conditioning. How different people describe their experience is a big part of the seeming variation in how phenomena present during this phase of practice, every single person has their own linguistic and semantic maps and, due to various factors too complicated to get into here, will describe their experience in different ways.
Whether or not that's "good enough" for you is only of concern to you, not to anyone else who's found using a conceptual map to be beneficial to their practice.
I believe that one-pointed concentration can trip the mind into some very unusual states. I believe this because the process has been corroborated by a whole bunch of non-religious people from a huge variety of different backgrounds. Some had altered states emerge through sport, running, trauma, fever, child birth and so on. I have no problem with people doing jhana to feel good and improve health. But if we were to look at the question: "what is a good, reliable and quick way to enter jhana?", then the answer would not be to turn yourself inside out concentrating on the breath for a few years. The answer would be to go to a good hypnotist and get him to spend 15 minutes with you. Just let go and follow along. Once you've got the swing of it, then do it yourself. Psychology. No need for confusing ancient religious texts. No need for prolonged retreats. No need for strict behaviours. No need for any of that Buddhist stuff.
Again, you've never actually practiced jhana and so your opinion is just an opinion. As far as using hypnosis to enter jhana, I disagree for several reasons: One of which is that I'm actually a trained hypnotist and had been experimenting with this exact approach years before ever knowing what jhana actually was; using hypnosis you can get as far as the early stages of 1st jhana but then there's a very specific method of going further which requires, not exactly "one-pointed concentration", but a far more dynamic and paradoxically 'fixed' focusing of attention.
You could feasibly teach someone
the techniques involved using hypnosis, or biofeedback, or any other of the various 'brain training' methods available, both meditative and technological, but using hypnosis to access jhana does not work. You're correct in saying that "one-pointed concentration can trip the mind into some very unusual states", hence the caveat that concentration practice does not lead to insight by itself, but again you're generalizing and making assumptions based on flawed data. You don't have the experience to comment on this beyond speculation.
Also, your suggested timescale of 15 minutes to induce a person and implant the required suggestions demonstrates a lack of knowledge when it comes to the basics of hypnosis. It would take
at least double that for the initial session, and, depending of the person involved, would take multiple session of reinforcement to actually bring them to a point where they can implement the techniques by themselves without the help of the hypnotist.
As for the "no need for any of that Buddhist stuff" comment, you're basically rubbishing 2,500 years of empirical testing and accumulated data which demonstrates that "that Buddhist stuff" involves a highly developed and reliable system of mental training that can be applied by anyone with the ability to do so. Just because you don't understand it doesn't mean nobody else does. That said, on the flipside I do think that it's possible to develop a system of 'spiritual' development divorced from traditional frameworks, but that's another story altogether.
I tend to believe the stages of insight have inherent problems. Lots of very good teachers say that the setting up of stages to complete is the ego's way of avoiding the Abyss. The Abyss is something that few ever contemplate entering. It's not wanted. Ego uses its most subtle trickery to give you the impression you are progressing towards the end goal. Got to stage 3? Ok let's set up a stage 3a and a 3b, then some cycling through 1a to 3b for a few decades so that you never end up getting to your destination. Cycling is the ego's last refuge. "I haven't progressed because I'm cycling".
For a start, you clearly have no idea what "The Abyss" or the experiencing of it actually involves so, yet again, you're bumping your gums and stating opinion as fact. The line I've emboldened is interesting and I'd like to know which sources you base your comment on? It's not entirely inaccurate and I'm pretty sure there will be people who use a linear system of development, attainments, goals and so forth, as a source of clinging; at the same time, there will be just as many who utilize conceptual models as means to an end, as a tool to orientate their practice but ultimately discarding them when no longer required.
Let's talk about "The Abyss" for a second 'cause you clearly don't know what you're talking about...the entire concept of "The Abyss" and the way in which its approached depends upon the model you're working with at that moment. If you're a magician, then "Crossing the Abyss" involves a literal battle with a 'demon' called Choronzon who, unless you've abandoned all traces of individuality and have sufficiently penetrated the subject/object dichotomy, will tear your entire psychological structure to bits and destroy you; If you're a Hindu, you don't encounter "The Abyss" as their model doesn't contain that. If you're a Christian Scientist, the experience is called "Chemicalization"; if you're an alchemist, it's known as "Nigredo", or the "Solve" stage of the "Solve et Coagula" formula.
So, when you talk about "The Abyss" you're only describing your own flawed understanding of it and, yet again, you don't have any experience of it to be able to speak about it beyond speculation. What "The Abyss" 'is' is the annihilation of subjectivity, beyond the Abyss there is no duality and no words can be spoken of 'it' because they are inherently false, which is a theme you'll find is universal in any traditions that include "The Abyss" or some similar stage.
You're sitting there criticizing stages and stages, but at the same time you're talking about "The Abyss"; this is just another stage or phase, just like the A&P, just like every other arbitrarily designated existing within every other 'spiritual' model from Buddhism to the Temple of Set. It's a convenient label, nothing more and nothing less; the sensate experiences those labels refer to are an entirely different matter.
I tend to think enlightenment is possible, but so what? I frequently get asked what I'm doing here on this forum, so there's my answer. It's of interest to me.
If it's of interest to you, why not actually do the practices described? You've already said before that you can't meditate, so go work with one specific model for at least a year, record your results in the same you would when doing a scientific experiment and then come back with the data and this might start to make sense to you. Enlightenment, or whatever you want to call it, is entirely possible, but it's not what you think it 'is' and you'll never know until it actually happens 'to' you.
I highly recommend checking out the work of Robert Anton Wilson, particularly "Prometheus Rising", he may offer a more useful, non-mystical way of looking at this that'll actually benefit you rather than leading you into constant conflict with people on here. I can see where you're complaints and objections are coming from, there's nothing new in what you're saying and the same criticisms have been leveled before, but without having the experience to back up your assertions, you're only giving an opinion, not stating facts.