Thank you for being honest and staying on the issues. Also, thanks for the desana by Ven. Sudassana.
In fact, the section of the desana that you selected has answers to the basic questions that we have been discussing: Bhava, Jati, Paticca Samuppada, Sotapanna and other stages of Nibbana.
Another key concept that has been hidden is “gati” (or “gathi”), that Ven. Sudassana mentioned. So, let me start there.
Based on our actions, speech, and thoughts (which are kaya, vaci, and mano sankhara), we accumulate various gati, which can be loosely translated as habits/character, but more like character.
Let us take person X. If X is capable of doing actions suitable for an animal, he has “animal gati”. These could lie in a broad range, for example, vicious animals kill, so if X can kill (especially a human), then he has gati suitable for an animal. On the other hand, if X has cultivated rupavacara jhana, and enjoys getting into rupavacara jhana, then he has cultivated gati suitable for a rupavacara brahma.
X may have many different gati, but one of the strong ones will determine the bhava that is grasped. So, if X has strong vicious gati suitable for an animal, X is likely to grasp a bhava in the animal realm. On the other hand, if X has dominant gati for a rupavacara brahma, he would grasp that.
As we saw in the movie “Earthlings”, animals in general undergo much harsh suffering. So, such suffering is possible for X, if X has some kind of “animal gati”. If X is a serial killer, he has gati suitable for much harsher realms in the niraya. If X has “excessively greedy gati”, X could grasp a “preta bhava” and be born a preta.
So, if one is habitually doing strong dasa akusala, one has ‘apayagami gati”. Here apaya includes the lowest four realms of niraya, preta, asura, and animal. By following the Noble Eightfold Path, X can get rid of such “apayagami gati”. Then one becomes Sotapanna.
The next higher 7 realms are the higher realms of the kama loka: human realm and the 6 deva realms. One gets a human or deva bhava by cultivating “human gati” or “deva gati”. But there is still suffering in these realms, even though less than in the apayas. As long as X is attached to sense pleasures, X will have those gati. When one comprehends the long-term dangers of sense pleasures, one would get rid of such gati, and attain the Anagami stage (via Sakadagami stage; I am making this brief).
Once one becomes an Anagami, birth is still possible in the 16 rupavacara brahma realms and the 4 arupavacara brahma realms. Even though suffering in those realms are much less, there is still suffering there. When one realizes that eventually, one loses “upadana” for such bhava also, and one attains the Arahant stage. That is Nibbana.
That is a basic outline. Of course, there is so many details. Those gati and bhava are fueled by Paticca Samuppada cycles that run each time X commits an akusala kamma (which cultivate apayagami gati) or punna kamma (which cultivate gati suitable for human and higher relams).
So, do you see why these concepts are much deeper, and much more complex than limited to a single life in the human bhava? Even in the human bhava, there will be many rebirths as a human. Human bhava shakti or energy can last thousands of years. So, one will be born human many times before that energy runs out. This is why there are accounts of rebirth. Of course, one cannot recall any other bhava.
These set of gati are also called “asava”. When all gati are removed, one becomes an Arahant. Then one will not grasp any bhava. This is why Nibbana is also called “asvakkhaya” or getting rid of asava.