If this indulgence in the subha nimitta of a dhamma were such a bad thing, why would the Buddha have recommended it as part of the Third Vimokkha or as the Subha Vimokkha?
Indeed, why would the Buddha have recommended it?
In fact, he never recommended it. Subha Vimokkha is related to the development of Metta.
There's nothing wrong with niramisa sukkha per se, if there's no attachment to it.
I see the Buddha teaching a gradual Path, and if niramisa sukha is not touched, how will His disciples desire to escape samisa sukha?
As to the blue
point, I think the Mettasahagata Sutta is not speaking of mettabhavana. It spoke of mettasahagata. Then, it speaks of karunasahagata which leads to the attainment of Infinite Space, it speaks of muditasahagata which leads to the attainment of Infinite Consciousness, and it speaks of upekkhasahagata which leads to the attainment of Nothingness. The inference from the sequence must be that the development of the 7 Enlightenment Factors accompanied by metta leads to the Jhanas.
As to the red
point, I have suggested that MN 44 makes it clear that there is no raga and no raganusaya when experiencing 1st Jhana sukha. You have opted instead for the Commentarial explanation, with which I disagree. Borrowing Ajahn Thannisaro's translation for convenience, with the key terms returned to the Pali and the key elision expanded-
"Does raganusaya anuseti with all pleasant feeling? Does patighanusaya anuseti with all painful feeling? Does avijjanusaya anuseti with all neither-pleasant-nor-painful feeling?"
"No, raganusaya does not anuseti with all pleasant feeling..."
"But what is to be abandoned with regard to pleasant feeling? What is to be abandoned with regard to painful feeling? What is to be abandoned with regard to neither-pleasant-nor-painful feeling?"
"Raganusaya is to be abandoned with regard to pleasant feeling. Patighanusaya is to be abandoned with regard to painful feeling. Avijjanusaya is to be abandoned with regard to neither-pleasant-nor-painful feeling."
"Is raganusaya to be abandoned with regard to all pleasant feeling? Is patighanusaya to be abandoned with regard to all painful feeling? Is avijjanusaya to be abandoned with regard to all neither-pleasant-nor-painful feeling?"
There is the case where a monk — quite withdrawn from kāmā, withdrawn from unskillful qualities — enters & remains in the first jhana: rapture & pleasure born from withdrawal, accompanied by directed thought & evaluation. With that he abandons raga. No raganusaya (latent tendency to lust) anuseti (underlies) there.
Sabbāya nu kho, ayye, sukhāya vedanāya rāgānusayo anuseti, sabbāya dukkhāya vedanāya paṭighānusayo anuseti, sabbāya adukkhamasukhāya vedanāya avijjānusayo anusetī”ti?
“Na kho, āvuso visākha, sabbāya sukhāya vedanāya rāgānusayo anuseti, na sabbāya dukkhāya vedanāya paṭighānusayo anuseti, na sabbāya adukkhamasukhāya vedanāya avijjānusayo anusetī”ti.
“Sukhāya panāyye, vedanāya kiṃ pahātabbaṃ, dukkhāya vedanāya kiṃ pahātabbaṃ, adukkhamasukhāya vedanāya kiṃ pahātabban”ti?
“Sukhāya kho, āvuso visākha, vedanāya rāgānusayo pahātabbo, dukkhāya vedanāya paṭighānusayo pahātabbo, adukkhamasukhāya vedanāya avijjānusayo pahātabbo”ti.
“Sabbāya nu kho, ayye, sukhāya vedanāya rāgānusayo pahātabbo, sabbāya dukkhāya vedanāya paṭighānusayo pahātabbo, sabbāya adukkhamasukhāya vedanāya avijjānusayo pahātabbo”ti?
“Na kho, āvuso visākha, sabbāya sukhāya vedanāya rāgānusayo pahātabbo, na sabbāya dukkhāya vedanāya paṭighānusayo pahātabbo, na sabbāya adukkhamasukhāya vedanāya avijjānusayo pahātabbo. Idhāvuso visākha, bhikkhu vivicceva kāmehi vivicca akusalehi dhammehi savitakkaṃ savicāraṃ vivekajaṃ pītisukhaṃ paṭhamaṃ jhānaṃ upasampajja viharati. Rāgaṃ tena pajahati, na tattha rāgānusayo anuseti.
In your earlier opinion, you offered your thoughts that the passage underlined red
should be read as extinction of raga through insight into 1st Jhana. This is how you read "with that"/tena. IMHO, the passage is very clear that the "tena" simply occurs at 1st Jhana, and not much later on enlightenment. The point to note is that the passage explicitly says that raganusaya does not anuseti with 1st Jhana pleasure.
If you look at how other suttas present raganusaya and how it anuseti sukha vedana, it becomes clear that raganusaya is the consequence
of raga. Eg from SN 36.6 -
Having been touched by that painful feeling, he resists (and resents) it. Then in him who so resists (and resents) that painful feeling, an underlying tendency of resistance against that painful feeling comes to underlie (his mind). Under the impact of that painful feeling he then proceeds to enjoy sensual happiness. And why does he do so? An untaught worldling, O monks, does not know of any other escape from painful feelings except the enjoyment of sensual happiness. Then in him who enjoys sensual happiness, an underlying tendency to lust for pleasant feelings comes to underlie (his mind).
Tassāyeva kho pana dukkhāya vedanāya phuṭṭho samāno paṭighavā hoti. Tamenaṃ dukkhāya vedanāya paṭighavantaṃ, yo dukkhāya vedanāya paṭighānusayo, so anuseti. So dukkhāya vedanāya phuṭṭho samāno kāmasukhaṃ abhinandati. Taṃ kissa hetu? Na hi so, bhikkhave, pajānāti assutavā puthujjano aññatra kāmasukhā dukkhāya vedanāya nissaraṇaṃ, tassa kāmasukhañca abhinandato, yo sukhāya vedanāya rāgānusayo, so anuseti.
Since MN 44 explicitly states that raganusaya does not anuseti 1st Jhana's pleasure, it becomes clear that the cause of raganusaya is also absent in 1st Jhana. That, in my view, is how "Rāgaṃ tena pajahati" should be simply read.
1st Jhana is not the only place where raganusaya does not anuseti a pleasant feeling. Raganusaya is not inevitable. I've mentioned previously that MN 152 seems to imply that an instructed putthujana practising satipatthana will not be touched by raganusaya. There is another sutta in the SN (references later, if you can wait) where the sutta explicitly states that 3 anusayas do not underlie the respective feelings on the occassion when the meditator undertakes the satipatthanas correctly. The sutta was not referring to an Arahant's meditation.
Of course, MN 138 as it stands directly conflicts with the literal reading of MN 44, plus the SN satipatthana sutta I mentioned. Let's see how Ven Analayo proposes that MN 138 may have suffered a transmission error, based on his comparison of MN 138 to the Chinese MA 164. I suspect that when the analysis is offered, any inconsistency between MN 138 and MN 44 will be resolved.