Sun's Significance

 Hari Om! In my humble opinion; 

1# these are all subtle aspects beyond the normal comprehension of our material conditioned human intellect.

2# whatever you are mentioning are symbolic Representative personifications, including the relationships and the idols we worship in temples or the physical sun, planets or stars are manifestations of the just 1 ultimate reality.

Let us not think the Gods' or Deities or the planets in terms of mere physical celestial bodies. They are only Representative-material manifestations and referenced in Puranas & Vedas episodes for our understanding with hints for us to think using our intellect to go beyond the material symbols.   

We all know, we cannot stand the sight of the Gods or deities with our physical Indriyas. We have examples to thus in Our Epics and all Puranas to suffice.

3# the creator, the ultimate reality & all deities are all mantra swaroopas(sacred sounds of vibrations) and are formless, as we all know.

4# by virtue of tapas sakthi the idols of temples are energized by the mantras for our rejuvenation during a devoted worship.

5# there is no question such non-existence before birth. Without the Pancha bhoothas there is no creation. 

Sun is all the energy @ creation and Agni is the fiery essence of the Sun & one of the Pancha bhoothas.  

The 7 horses represent the 7 ray bands of the material plane's physical sun's monochromatic beam of light.

We need to think laterally away from material existential frame to comprehend.

Jai Hind! Jai Sanathana Dharma! Jai PD Community!