1. I think the simple interpretation here is that the person who swallowed the Zibura has such a short time left to live that he will not have the clarity of mind to command his house about more spiritual matters, so we say that at any rate he may be able to put the financial matters in order, which is also important.

2. I can add on to your question the Gemara above 47a which relates how Resh Lakish was upset that when he died he bequeathed a Kav of saffron to his heirs.

However I think the explanation is that these great Tzadikim spent their whole life toiling only on Torah and Mitzvos so they felt their time was wasted in accumulating material possessions for others. Ordinary people however spend a significant part of their lives accruing financial gains, and feel upset when this toil does not go to the people they wanted it to go to. See Bava Basra 156b that one may waive aside the Rabbinical prohibition of making a transaction on Shabbos so that a seriously ill person's health should not deteriorate because he fears his wishes are not being fulfilled.

In contrast the legacy of the great Tzadikim to future generations is their words of Torah and their spiritual teachings, and they do not see their role in life to be the transmitting of material wealth.

3. It certainly may help if people make clear what roles they want their descendants to follow after their passing.

4. We should all daven that our descendants and family should live peacefully together, not only after we die, but also in our lifetime!

Kol Tuv

Dovid Bloom