If a question raised by a Theravadin, normally I don't bother. However, since I learnt the Dharma from Chinese Tripitaka, with Mahayana doctrines the main teaching while basic doctrines listed in the Agamas, I have the knowledge to understand Theravadin doctrines as well. For Pali Canon is roughly equivalent to the Agamas. In this respect I think I can contribute to this question.
I didn't read Buddhadasa Bhikkhu's Anatta and Rebirth, consciously choose to spend time reading the most superior writings, for life is short, time is pricey. I've read Bhikkhu Yuttadhammo's answer by accident, and for writing this post I read his comment and another answer linked by OP, briefly. Therefore, my answer should just be regarded as some highlights to help solving questioned topics.
- Explanation Y supports both #5 and #6 above.
No. My reading OP's links of Y doesn't support 5, nor 6.
Y rejecting 6 in this writing:
There isn't in fact any such thing as rebirth, in ultimate reality...
Rebirth is a concept used to describe the change between one
artificial framework of experiences (e.g. a human life) to another.
In another answer, Y clearly stated he rejected "rebirth", he accepted "birth" only. Rejecting 5 in this answer:
The ultimate reality is that the mind simply arises and ceases at the
last moment of life and then a new mind arises at the first moment of
rebirth based on the last one, very similar to as has been occurring
throughout one's life, except this time there is no old physical
phenomena for it to be based on, so it is based solely on one's final
state of mind in the last life.
However, it seemed Y is contradicting himself, quite confusing wordings. For on one hand he stated there is only "birth", no "rebirth", on the other he said the new mind is based on the last one.
If you plant a new tree, does it based on the last tree to plant? No, if you based on the last it's called grafting plant - joining two or more into one plant. Even planting a new tree, you need the seeds from the old tree, therefore there isn't any "new mind" can arise independently, as Y wishes. Using the word "birth" or "rebirth" doesn't give Y any edge to defend his view.
Y further confused his concept with this wordings:
Every experience that is made up of the five aggregates arises and
ceases without remainder.
This is a questionable explanation, perhaps Bhikkhu Yuttadhammo is limited by language to explain his meaning. Simply, memory remains, isn't it? Also the experience of previous conditions the response of next experience, and the effect of previous also affects the successive experience. This can be proven in daily life, by common sense.
OP's question 1 & 2:
No. Bhikkhu Buddhadasa (wrongly) rejected the continuity of suffering beyond physical death. I procured his view from my "scanning", and reading titles, his article(s) on rejecting the existence of heaven and hell is the proof.
And perhaps likely B was bearing the fruit of his own incorrect understanding that led many followers astray. I read some articles on the internet about B's final moments. He suffered extreme pain, lost consciousness; against his last wish to abandon medical means to continue his life, he was put to surgery, and many different treatments that only gave him severe pain, without reviving or relieving him from his suffering state.
It made me recall what I learnt from other Sutras, that a being reappeared in hell doesn't take physical birth, just manifested as a body-less (consciousness) being. In this sense you can say it not a "rebirth", for it directly appears in another realm. Because it doesn't have physical property, it can't die, no matter how terrible the suffering or mutilations it went through millions times. (One can understand this by inferring to the suffering or mutilation happened in dream, in dream there is no physical body too.) Usually one's most strong belief, or defilement, will manifest as the most prominent scenario.
OP's question 3:
I suspected Bhikkhu Sati is limited by the terminologies he could choose from the Pali Canon, therefore he used the confusing word "consciousness". I infer he was trying to explain the Theravadin doctrine of no-Self in terms of Five Aggregates and the consciousness to give proper explanation of how rebirth should be understood/ could happen. Good try, but unfortunately short of resources to support him in the Pali Canon.
Instead of entangling in the arguments of the two Theravadin Bhikkhus for trying to understand the doctrine of rebirth and no-Self, here I would like to contribute by giving resources from the Chinese Tripitaka. From my study, Mahayana (excl. Tibetan) is the complete teaching of the Buddha. Rebirth should be understood with reference to the Alaya-vijana; and no-Self should be understood, in particular, with the Mano-vijana. We understood Alaya, or Tathagatagarbha, is the essence that doesn't birth, nor die. It never arises, nor ceases. (I think Bhikkhu Yuttadhammo was trying the words "ultimate reality" but his lack of Mahayana resources made him confusing in his understanding). And this 8th consciousness is not the Self, because a Self by definition has attributes, cannot be universal. It is by this meaning the no-Self (Anatman, Pali: Anatta) is realized. However, it is neither not the Self, for every sentient has the Alaya, it is by this definition Alaya conjoined with Mano-vijana to create the conventional self - the "I, me, mine". This two vijanas will not be cut off when physical death happened.
Since this forum the majority are Theravadins, I felt it is futile to let most readers understand therefore I will not give further explanation.
It is incorrect to dilute the doctrine of no-Self replaced it with the term "self-view". It is important to understand that though in Ultimate it is no-Self, there is "me-self" for any unenlightened being. It is this false "me-self" that traversing in death-rebirth. Those who wanted to reject rebirth by the doctrine of no-Self, they should ask themselves, if they cut their fingers do they feel the pain? If they do, then they are far away from getting rid of this "me-self". (Because if an entity is just a pile of Five Aggregates, it won't feel; if it is consciousness, since the Theravadin consciousness is momentarily mind-contiuum, it will not feel pain either. How can a moment pass information to another moment? Isn't the time of cut and pain occurred in two different moments? If they occurred in same moment, it will be there is no cut but there is pain, or there is pain but there is no cut, isn't it?) They will be reborn after physical death, no matter they accept it or not. It is definite, guaranteed. Another inference, simply, by universal law, if a thing doesn't have a beginning it will not have an end. Can anyone recall when the moment the notion of "I" begins?
Now let's deal with why Theravadin doctrine so easily interpreted by sincere followers to reject rebirth. My assertion is, the main reason that Theravadin doctrine teaches the Five Aggregates no-Self, the consciousness are momentarily continuum also no-Self. Now problem, what gives to keep the continuity of a being by the time of death? They conclude the no-Self should be the final truth therefore rebirth is a myth, or a mean simply to strengthen morality, or to appease the ancient Indian audiences... etc. etc. I do sympathize these followers and reckon their sincerity in following the doctrines. Though they wrongly interpret the literal word "rebirth" of the Buddha due to their lack of comprehensive resources. If they have the minds for studying Mahayana Sutras, their questions stirred up by the conflict of no-Self with rebirth will be answered by themselves satisfactorily.
The above infers this: it is unfortunate many taken and conditioned by the views invented by those scholar-Buddhists, advocating the so-called "Early Buddhist Text" or "Early Buddhism". These views never appear until late 200 years, when the world was taken by colonialism. Bhikkhu Buddhadasa (he had correspondences with some associated with Anagarika Dharmapala) was one of those suspected groomed (secretly) by the Theosophical Society that established the Southern Church (Theravada School) in South East Asia during colonization of Sri Lanka. The Northern Church was established based on the Tibetan doctrines. And the Sri Lankan Bhikkhu Anagarika Dharmapala, after receiving the helps from the Theosophical Society to re-establish the Sanghas, he had chosen to break with them before he submitted to their purpose of creating a "universal religion", combining Buddhism, Christianity, Islam, Judaism... etc. into one religion. Brave fellow!
As I'd been confused by many statements of those who disparaging Mahayana Sutras when I first joint this forum, I did quite in depth studies and readings to clarify what really is the truth. Unlike some Sri Lankan who's quite patriotic, I have no difficulty of taking any school as my personal preference and reference, as long as it is the Buddha's authentic teaching, or even taken more than one. But my researches lead me learnt the above facts regarding how Buddhism was shaped in recent 200 years.
In fact, it is with plenty evidences and references the Mahayana Sutras in Chinese Tripitaka are authentic Buddha's own words. These Mahayana Sutras, together with the Four Agamas, were written down at the gathering in the Cave of Seven Leaves after Buddha entered Nirvana, called the 1st Buddhist Council. The teachings, consisted the 12 sections of Sutras with large portion are Mahayana Sutras, were written on plain cloth to be kept and transmitted, instead of the commonly and widely spread Theravadin saying - by oral recitation. The more interesting fact is, the original Sri Lankan School were Mahayanist, the Sthaviravāda were Mahayanist (who Theravadins claimed and associated to be their inheritor). Interested readers may read the details, records, and quotes of evidences regarding the 500 Arhats collecting the teachings, the 1st Buddhist Council.
By saying the above I don't mean Pali Canon unauthentic, it is good enough for teaching the basic doctrines, and very suitable for beginners, if they can interpret it correctly. I only want to give confidence to those who ready to receive the Mahayana teachings, that Mahayana Sutras are Buddha's own words. The other point I want to make is, without getting the complete teaching of the Buddha, particularly the doctrines on Alaya and Tathagatagarbha, it is almost impossible to understand the doctrine of no-Self and rebirth, in its comprehensiveness. From my study and understanding, the teaching of Alaya and Tathagatagarbha has already mentioned in the Agamas. But it is not elaborating as so profoundly in the Mahayana Sutras.
To conclude, rebirth is a fact for unenlightened sentient. It can only be rid off when enlightened. Enlightened is one realized no-Self. One realized no-Self is an Arhat. An Arhat has no rebirth. In Ultimate, there is no birth-death, i.e., no rebirth, Ultimate is the Alaya and Tathagatagarbha. The Chán School (Jap: Zen) may put aside or play down the doctrine of rebirth, for they focus on realizing the Tathagatagarbha, the self-Nature.