2).
Soma is even older than the Vedic Indra as slayer of Vritra and snakes.

Several Indo-Iranian epithets survive (of _soma_ and _haoma_, respectively), and among those of Iran is the title 'Vritra-slayer,' applied to _haoma_, the others being 'strong' and 'heaven-winning,' just as in the Veda[26].

All three of them are contained in one of the most lunar-like of the hymns to Soma, which, for this reason, and because it is one of the few to this deity that seem to be not entirely mechanical, is given here nearly in full, with the original shift of metre in the middle of the hymn (which may possibly indicate that two hymns have been united).
To SOMA (I.91).
Thou, Soma, wisest art in understanding; Thou guidest (us) along the straightest pathway; 'Tis through thy guidance that our pious[27] fathers Among the gods got happiness, O Indu.
Thou, Soma, didst become in wisdom wisest; In skill[28] most skilful, thou, obtaining all things.
A bull in virile strength, thou, and in greatness; In splendor wast thou splendid, man-beholder.
Thine, now, the laws of kingly Varuna[29]; Both high and deep the place of thee, O Soma.
Thou brilliant art as Mitra, the beloved[30], Like Aryaman, deserving service, art thou.
Whate'er thy places be in earth or heaven, Whate'er in mountains, or in plants and waters, In all of these, well-minded, not injurious, King Soma, our oblations meeting, take thou.
Thou, Soma, art the real lord, Thou king and Vritra-slayer, too; Thou art the strength that gives success.
And, Soma, let it be thy will For us to live, nor let us die[31]; Thou lord of plants[32], who lovest praise.
Thou, Soma, bliss upon the old, And on the young and pious man Ability to live, bestowest.
Do thou, O Soma, on all sides Protect us, king, from him that sins, No harm touch friend of such as thou.
Whatever the enjoyments be Thou hast, to help thy worshipper, With these our benefactor be.
This sacrifice, this song, do thou, Well-pleased, accept; come unto us; Make for our weal, O Soma, thou.
In songs we, conversant with words, O Soma, thee do magnify; Be merciful and come to us.
* * *[33] All saps unite in thee and all strong powers, All virile force that overcomes detraction; Filled full, for immortality, O Soma, Take to thyself the highest praise in heaven.
The sacrifice shall all embrace--whatever Places thou hast, revered with poured oblations.
Home-aider, Soma, furtherer with good heroes, Not hurting heroes, to our houses come thou.
Soma the cow gives; Soma, the swift charger; Soma, the hero that can much accomplish (Useful at home, in feast, and in assembly His father's glory)--gives, to him that worships.
In war unharmed; in battle still a saviour; Winner of heaven and waters, town-defender, Born mid loud joy, and fair of home and glory, A conqueror, thou; in thee may we be happy.
Thou hast, O Soma, every plant begotten; The waters, thou; and thou, the cows; and thou hast Woven the wide space 'twixt the earth and heaven; Thou hast with light put far away the darkness.
With mind divine, O Soma, thou divine[34] one, A share of riches win for us, O hero; Let none restrain thee, thou art lord of valor; Show thyself foremost to both sides in battle[35].
Of more popular songs, Hillebrandt cites as sung to Soma (!) VIII.

69.
8-10: Sing loud to him, sing loud to him; Priyamedhas, oh, sing to him, And sing to him the children, too; Extol him as a sure defence....
To _Indra_ is the prayer up-raised.
The three daily _soma_-oblations are made chiefly to Indra and V[=a]yu; to Indra at mid-day; to the Ribhus, artisans of the gods, at evening; and to Agni in the morning.
Unmistakable references to Soma as the moon, as, for instance, in X.
85.

3: "No one eats of that _soma_ which the priests know," seem rather to indicate that the identification of moon and Soma was something esoteric and new rather than the received belief of pre-Vedic times, as will Hillebrandt.