The purpose for those images is in a different context. In Exodus 20:4 we are talking about worshiping and in the later verse God is telling the Jews to put up images for none-worship purposes.
The Ark of the Covenant, where the mercy seat was in between the carved images of the Cherubim was most certainly bowed to and worshiped, seeing it as God's throne mystically to the Jews.
Also, you have just said God had Moses put up
images in the Temple for non-worship use. You have just affirmed what we practice and that images were certainly in the Temple and were not banned or prohibited.
The bible says nothing about he saw God and since the bible clearly states in 6:46 that no one except from Jesus Christ has seen the Father, I will say that he didn't see God.
Actually, it does.
Exodus 33:18 "Moses replied, 'Reveal Yourself to me." 19 Then God said, 'I will pass before you in My glory, and I will proclaim My name, the Lord, before you. I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion.' 20 But He said, 'You cannot see My face for no man can see My face and live.' 21 Moreover, the Lord said, 'Here is a place by Me you shall stand on the rock. 22 So it shall be, while My glory passes by, that I will put you in the cleft of the rock, and will cover you with My hand while I pass by. 23 Then I will take away My hand, and you shall see My back; but My face shall not be seen."
That was Christ's back Moses saw.
Jesus Christ is the image of the Father, but I still haven't seen any image that is able to represent Christ correctly and I doubt that will ever happen. It's also impossible if you try to make the image portrait His divinity.
Nobody is trying to make the perfect Image of Christ God. It is not like we are trying to do a sitting portrait of him or snap a photo. The point is that Christ came in the flesh, in matter, came onto the earth and took on humanity and rejoined it with Himself and reconciled it to the Father. God showed us who He was in the flesh, making it possible for us to see who the Father is through Christ. Therefore, in testament to Christ's Incarnation, the holy icons show this.