a) I have read a big part but it is difficult to understand as the English is in very high style. If you could make a resume, then i won't have to read it. If you also know the part of the business partner you could tell page number.
It should also be verified if this same busines partner is the one from Calcutta, because having a big buisness Brahma Baba could have more than one partners. Is it the same one that is mentioned in the Murlis with the letter that Brahma Baba used to send him ..."Alaf got Allah, Be the badhshai (not sure of the spelling - kingdom)". Because now that he owns the whole business then would he leave Calcutta and the business to come to Sindh. Who would take care of the business? There is not the mentioned what has happened to the perishable jewel business after Brahma Baba retired. Maybe the partner could have come from Calcutta to Sindh for a little time. From the clarifications, we know he never went to Karachi but Brahma Baba left to Karachi just because of their misunderstanding.
Regarding Prajapati, i think we should better stick to these stories rather than the documents because as it is also mentioned in the story that this literature used to be prepared especially for sending, and it is even visible on seeing them, so it is very likely that they contain the information an a dressed up way, like the literature of today is far away from the real knowledge. In comparison such stories that resemble revelation, surely will also contain PR, but maybe less.
It is interesting that in the Murlis it is mentioned the early period where it used to be thought that the soul is thumb like etc. So the one who has spoken the Murlis is somehow aware. It is obvious that Gyan has changed and this fact does not make it false.
If there has been a conspiration made to cover up the past, i don't think it has been made deliberately and in one occasion. With the course of time even one's own perception of the past can change. It is also not nesesary that everyone has been influenced and involved in the conspiracy. We could find examples.
b)I thought that The Tree story matches with both the Dadas. Just now you said just that.
There is a story of The Tree and Cycle to match with Vishwa Ratan's
It is also interesting the way Brahma Baba used to joke with Kumarka Dadi. And also the case of giving money to someone he has acted more like a rich person and pop star rather than considering the wealth to be precious Godly wealth. It is also visible that he has been fond of massage. Life of leisure and comfort, as we are thought in the advanced knowledge with his easy posture on the picture of the Trimurti, in comparison to the strict Shankar.