ekaṃ sad viprā bahudhā
Indeed.
We are sun worshipers, but not solely so. As you show awareness of, the sun perceived by the senses and delivered through the sensorial mind, manas, to the intellect is not the true Sun. Intellect, bridged by cit kala confers the status of Purusha. This is what gayatri is, the request to bridge the intellect to the noumenon by purifying through the sun's rays.
Yes, the inner and the secret sun are of vital importance in our religion. We must understand it however in the larger overall context.
Firstly, what is a mandala? It is a concentration of energies and identities which also concentrates the aspirant's focus. As you call them both the vishrutha and the samasthi methods involve disparate rays and a unified focus, whether proceeding outwards or inwards. There is another third form of worship, but we won't go into that here. It is also said there is a secret fourth.
Anyway, the mandalas of the Vedas are invoked through Richas - the hymns of the Rig Vedas. This is equivalent to the vedantic & agamic prana pratistha. The mandala is recognized as pervading all reality, irrespective of artificial, egoborn division between the inner and the outer. The Self is transposing its internal divinity into the external reality, or recognizing the samarasa of the two.
In overapplying Western concepts of Monotheism, which certain circles of Indians have learned to curry favor with, we run the risk of losing the essence of the Vedas.
We are Sun worshipers, we are Moon worshipers, we are Fire worshipers.
And none of these are what men and dictionaries call as per the sun, the moon, and the fire, rather they are the cognates.
The physical reality is wholly constructed of devas arranged in mandalas and vahanas, orchestrated as per the music of the vedic meters and hymnal divisions. Their tanuu spreads itself through all the elements of the outer world (the Vasus), the Inner World (Adityas) and that which seams the two (the Rudras). Presiding over this weaving of the devatanu (
Indra's net) are two corollary entities of Indra and Prajapati. Indra is the penultimate Lord, Prajapati the ultimate.
This is the
guhya samaja mandala, reflected almost perfectly in the Vajrayana Buddhist tradition of the same name. Truly, the Vedas are preserved in the agamas, even and perhaps
especially within Buddhism.
It is key to note that Indra's vajra
reveals the sun. What is the meaning of this?
All of the mandalas are important, all of them. All of the deities are important.
To go back to what I was saying about cognates, the physical sun, moon and fire are representative of particular devas, and sets of devas which confer vidya and siddhi. All devas are manifest everywhere - devas are transdimensional beings whose protrusion into our limited-dimensional, simulated reality manifest as particular elements. Symbolically and qualitatively, certain deities are more manifest than others in certain substances. We identify through the outer sun with the inner sun of the enlightened intellect and the spreading and collection of the rays of consciousness (secret sun), and so forth.
The belief system itself is nigh worthless. People gain almost nothing by merely being reminded of the identity of Hiranyagarbha. It gains relevance only when it translates into practical understanding and practice.
Identities are as much veils as anything else. That spreading and collection of consciousness is a function of our capacity for attribution - earlier discussed as the dichotomy between vacaka and vakya.
This is what ought be focused on, not trumpeting from the rooftops what little we have learned under the mistaken assumption that it is, or ought be, a revolutionary shift in the thought of the current amnayas.
Frankly, you have acquired a particular, narrowed view on the Vedas, whether through fault of the scholar you are informed by, or your own reading of him. The Vedas must be taken fully, in context.
Basic point I want to make is this: We need to understand our esoteric relationship with the Sun, but we should not overemphasize the sun aspect and lose the other, greater aspects which, beyond the Sun, include kāla, kalā, vyoma, shunya and, of course, the atattva. All the traditions we currently have contain this.