I remember reading this back then but deliberately held back any comments. However would like to say something
1. You are right about Rama = VishNu + Shiv, and again the 2 are same and different like dhUp-chaunv (sunshine-shade). On Shri RAma NavamI 2006 I was given the realization that
"I"/HE/THAT = Buddha/TapasvI Yogishwar -- Shiva -- RanganAth (RAm-in-RanganAth-pose which I did not notice at the time, and had no clue up until say 2013 that RanganAth is Rama's IshTa) -- ... one week ...-- VishNu (final)
However, this is only regarding His purusha-tattva aspect. Ultimately He is that NArAyaNa.
What the dasha(10)- mahAvidyA map above is showing is the role of YogamAyA in the avatAr's manifestation. So if tArA is the mahAvidyA associated with rAma that is also correct. Notice the Buddha darshan in what I wrote above. (Buddha-tArA) , and RAma is more tilted towards ascetism, was the target of VasishTha muni's YogVasishTha.
2. Shri KRshNa: You and they are both right. Shri KRshNa says in Bhagavd GitA He manifests on earth in association with His YogamAyA -- and Him being the pUrNAvatAr is speaking for all the above avatars. Also, He has clear-cut assignments for His YogamAyA - go and be born as YashodA's daughter. Them come here and do this that.
Shri LalitA TripurAsundarI is the ultimate all-encompassing Devi from Shri VidyA standpoint, but KAlI and LalitA are 2 sides of the same coin.
While KAli is the sauMhAra aspect of KRshNa (annhilation of evil - yadA yadA hi dharmasya, mahA-kAla, "kAlosmI" ) , Shri LalitA is the prem-leelA aspect.
Since He is pUrNa He choses YogmAyA in pUrNa form which is LalitA who transforms into KAli on the battlefield of Kurukshetra as well as Shalya , KauMsa, rAkshasa-uddhAr. UddhAr - because His compassion for the rAkshasAs including pUtnA is amazing and this is the motherly aspect of kAlI.
Shri KRshNa is first a Mother to His devotees (This is the motherly instinct of nArAyaNa, VishNu combined with motherly nature of KAli) He literally nurtures those who truly come to Him. Even the leelas with Gopis - He is actually nurturing them as ParamAtmA. Trust VishNu to do that -- in Rama and KRshNa avatar, you will find both male and female devotees putting their head in His lap. Lakshman, Bharat Shatrughna , Sita -- Shri RAma. Radha, gopis, Uddhav, Sudama -- Shri KRshNa. Numerous devotees of today also automatically put their head in His lap.
Yes, this is correct and in accordance with what Shri KRshNa says in the Bhagavad GitA - -that He descends via His YogamAyA. There is no contradiction with the Shakti texts like Devi BhAgvatam in this case because they are simply looking at the same Divine Phenomenon from a different (perhaps topsy-turvey) perspective. "VishNu cannot manifest in the material world without the shakti which He calls YogamAyA" This shakti when acting on normal ordinary creation is MahAmAyA and causes ignorance and entanglement of jivas.So, you can see that I am really striving to go in this direction -> it appears to me that the 10 different avataras of Shakti devi are presiding deities of different chakras of the body and that Sri Vishnu in connection with each of these energies, manifests as either form of the dasavataras.
You are right in saying that Sita is the combination of all Shakti tattvas because since Rama was ek-patnI-vratA His shakti-consort (SitA) had to have all Shiva-VishNu-BramhA shaktis combined, unlike KRshNa who could distribute 8 shaktis among 8 consorts. and their expansions.Lastly, I understand what you are saying w.r.t Smt Radha Rani -> That she is a combination of Lakshmi, Durga and Saraswathi amsas and this combination of all 3 amsas is what I am referring in this thread as 'Sita'.
Shri VidyA says Shri i.e. LalitA tripurAsundarI is the ultimate pUrNa Devi. However the emphasis of the Shri VidyA path is on mechanics of creation and manifestation (Shiva-Shakti), pinDanDa-bramhAnDa corelation etc.
Whereas, when GauDIya VaishNav say RAdhA is the fountainhead of all shakti spectrum, what they mean is :
If you filter out all the creation-annhilation aspects of the Shakti , and simply sift out the purest prem tattva untouched by material/creative-maintaining-punishing motives, where the objective is nothing but alhAd , to enhance the pleasure of the Ultimate PUrNa Purusha Shri KRshNa in a very selfless way, and Whose focus is none other than prem-lIlA with Shri KRshNa , ArAdhanA of Shri KRshNa (so much that He worships Her too), with no other distractions -- of other bhAvas or missions, motives,
--- what remains is RAdhA.
Hence from the perspective of the GV dheya (goal), which is KRshNa prema , RAdhA is the fountainhead of all shaktis. Even Lakshmi is sometimes seen bestowing material abundance on the world & auspiciousness and good qualities for good living, but RAdhA is only associated with shuddha bhakti. Hence the GV siddhAnta says that Radha is higher.
What higher means depends on who is asking/telling , from what angle. The same Devi transforms into shades and bhAvas depending on the moment and comes around full circle.
What bramhajijnasa says above about the various forms of NArAyaNa being eternal is also correct, and this is svAnubhav. However, my anubhav tells at least Shri KRshNa/NArAyaNa, RAma, NRsiMha, HayagrIva, VarAha, is the same One in those forms, not different Ones, although they have not all revealed pUrNatva like KRshNa/NArAyaNa has. (I will not say that about all the aMsha and shaktyAvesha avatArs who are empowered beings byVishNu rather than VishNu Himself)
Now you may say who is denying that and what's new about it -- but please tune in and hear the subtle implications of what I am saying --- all those forms -- although co-existing, are really my same PrabhU. They are not different Persons. As the various forms have changed shades of bhAva and purpose, so does LakshmI change shades of bhAva. Hence each is associated with a special form of Her.
P.S. Oh and regarding your most recent post -- Shri RAma as TrimUrti is also nothing alarming when we see what Shri KRshNa says in the Bhagavad GitA. Of cource the TrimUrtI is a transformation (guNa avatAr) of the Supreme Parameshwar, ParaBramhan' Who is Shri KRshNa or Shri RAma for devotees of RAma.
The tradition of Shri Gurudeva Datta (DattAtreya) is also meant to convey the same -- "the One I worship is the Ultimate Brahman' through this form and hence this form is a combination of TrimUrti" Technically, Datta (Atri's son given in dAna = Datta + Atreya ) is VishNu pure, and BramhA became Rshi Chandra, Shankar became Rshi DurvAsa. Yet, people worship Datta as the TrimUrti.
I like the ek-mukhI Datta at NArAyaNpur (One face, 6 arms - ayudhas (weapons/what they hold) are a symbolic blend of TrimUrti ayudhas). Now it is different that the bhAva here is quite different for those who want to see the difference.