Here's the quote from your point by point summary:
>>ONE WHO FEEDS ANOTHER
(a) Question: If Reuven feeds Shimon, must Shimon wash?
(b) Answer #1: Rav Huna bar Sechorah fed Rav Hamnuna; he said, 'If you were not such a Tzadik and Chacham, I would not feed you.'
1. Suggestion: He would trust only someone as zealous as Rav Hamnuna not to touch the food.
(c) Rejection: He would trust only someone as zealous as Rav Hamnuna to wash beforehand.<<
My question: it appears that the "rejection" is equally a proof that a mapa does NOT take the place of netilas yadayim for most people. In the hava amina, it does not take the place of nt"y for all BUT Rav Hamnuna, in the maskana not even for him. Either way, why is the ibayeh not resolved at this point?
Thank you, apologies for "ki kai Rav behai mesechta" and best wishes for a kesiva vachasima tova and the koach to continue your wonderful work.
Gershon Dubin, Brooklyn NY
Let me tell you how I understand the Gemara, and I think your question will dissipate.
Suggestion: Irrespective of Rav Huna bar Sechorah's personal prejudices, if, as we initially think, he was referring to Rav Hamnuna's Zehirus (in being careful not to touch the food), then it is clear that as long as the person being fed is careful not to touch the food, he is not obligated to wash (see Rashi).
Rejection: It is however possible that he was referring to Rav Hamnuna's Zerizus (in having washed in advance), leaving us with two possible interpretations of his words, in which case we have no proof what the Halachah will be.
In a nutshell, it is not a Havah Amina and a Maskanah, but a Havah Amina (or suggestion, as you call it) and a Dichuy.
Wishing you and yours a Kesivah va'Chasimah Tovah.
Kol Tuv
Eliezer Chrysler