О вечности (???) души

Где ты там прочитал "атман"?

Нет там такого смысла, ты его туда приписал.

живые трупы

По пунктам: 1. Архат полностью прекратил тягу к любому текущему и будущему существованию. (согласен или нет?)

2. Архат тем самым прекратил причины для нового рождения. (согласен или нет?)

3. В момент смерти тела текущие скандхи угасают полностью. А у архата не возникают новые, так как нет причин. (согласен или нет?)

4. Если после паринирваны архат продолжит некое бытие, то это нельзя будет назвать паринирваной. (в контексте тхеравады) (согласен или нет?)

Тогда уж вечной нирваны.

Прекращал он не клюбому, а к трем видам и только про прекращение этих трёх видов и можно говорить.

Назови причину с чего им угасать полностью в момент смерти?

Для нового сансарического рождения, которое он прекращал - да.

Паринирвана, это тоже самое, что и нирвана = обретение архатства. После этого архат остается в сознании, живёт, хотя по идее уже в нирване. Но ты видимо имеещь ввиду - что будет после смерти архата? - Будда учит, что про это ничего нельзя утверждать.

А разве психика, ум в буддизме - не поток тех же самых, только нематериальных дхарм (если я правильно помню, их 5 групп)?

     45. If your objection is that liberation is due to the elimination of mental afflictions, then it should occur immediately afterward. Yet one can see the power of Karma over those people, even though they had no mental afflictions.
     46. If you think that as long as there is no craving there is no grasping onto rebirth, why could their craving, even though free of mental afflictions, not exist as delusion?
     47. Craving has its cause in feeling, and they have feeling. The mind that has mental objects has to dwell on one thing or another.
shantideva.net/guide_ch9.htm

     45 If your objection is that liberation results from the destruction of the defilements, then it should happen immediately afterwards. Yet one can see the power over them even of undefiled action.
     46 If you put forward the argument that they have no craving leading to grasping,
[our response is:] Even if their craving is undefiled, does it not exist as delusion?
     47 Feeling causes craving, and they do have feeling. A mind which has objects will get stuck on one or another.
The Bodhicaryavatara By Santideva, Kate Crosby, Andrew Skilton, Paul Williams
http://books.google.com/books?id=m-ifbE8kyGIC

   45. You say there's liberation in the instant
       That defilements are entirely forsaken.
       Yet those who from defilements are set tree
       Continue to display the influence ol karma.
   46. "Only for a while," you say. "For it is certain
       That the causes of rebirth, their cravings, are no more."
       They have no craving, granted, through defilement.
       But like their ignorance, why should they not have craving undefiled?
   47. This craving is produced by virtue of sensation,
       And sensation, this they surely have.
       Concepts linger still within their minds;
       And it is to these concepts that they cling.
The Way of the Bodhisattva: (Bodhicaryavatara), Revised Edition (Shambhala Classics)
Shantideva, Padmakara Translation Group
http://www.amazon.com/dp/1590303881/

Будет цепляться за то или другое

to dwell on one thing or another

get stuck on one or another

However, in the Buddha’s definition of the craving that leads to renewed
becoming, he states that one of the primary functions of craving is as a locator:
choosing a location to relish, around which a state of becoming can form.

“And this, monks, is the noble truth of the origination of stress: the
craving that makes for renewed becoming—accompanied by passion &
delight, relishing now here & now there ….” — SN 56:11

Thus the moisture of craving is a type of kamma that chooses which seeds,
planted where in the field, will grow. Only the seeds moistened in this way will
develop into states of becoming. In other words, the mental qualities of passion,
delight, and craving select a particular spot in experience to focus on, and in so
doing provide a place for becoming to be produced. This is why discourses such
as Sn 5:2 and Thag 14:2 describe craving as a “seamstress”: It stitches the
elements of becoming together, like a button on a piece of cloth, in a particular
place.

This stress is compounded by the fact that craving and clinging are so
haphazard and erratic. As the standard definition of the origination of stress
notes, they relish “now here, now there.” They can change their focus at any
moment, abandoning the construction of one state of becoming to start work on a
new one.
http://dhammatalks.org/Archive/Writings/TheParadoxOfBecoming.pdf

Прасангика: В сансаре движется и перерождается индивид, признаваемый (существующим) (т.е. условно существующий) в связи и по отношению к скандхам (т.е. к изменчивому и причиннообусловленному потоку дхарм).

Благородную личность на Пути удерживает бодхичитта.