What is a pseudo-Jinchuriki, anyway? A fan-made term, I presume. Your thread and the factual statement it carries is wrong from the get go, as tailed beasts are nothing but masses of chakra. Not once in the manga is it ever mentioned that they even posses any 'human aspects' of the soul, but the term 'physical manifestation' is employed to get the idea across. Chakra itself is mental/spiritual energy.
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Your other point about the death god's belly is completely incorrect, as Minato would fight with what exactly when he took away Yin chakra that disturbed Kurama's form/shape only?
This is explained effectively through Obito's revelation about Izanagi or the creation of all things used by the Sage to give form to and breathe life into things.
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. Going by this scan, Yin is about the physical form and Yang is about the soul.
If one takes this into consideration then the entire basis of Kyuubi's size reduction is because its Yin chakra was ripped away. The soul and the actual consciousness STILL resides within Naruto. There is no weight in your theory whatsoever.