No, my understanding of "first born of all creation" doesn't mean He was doing things. Paul said Jesus was the first born of all creation. That would indicate that He wasn't there for millions of years prior to the creation. However, from creation to the incarnation He created creation and was in it doing the work of God. I think you're being facetious as to whether He was sitting or standing.
The Firstborn of all creation is the firstborn of all things created or the first of Gods works. Before all other things except His God the Father. His spirit was formed. The fullness was not formed but gifted. As in the fullness was pleased to dwell in Him. Jesus is not nor ever has been a angel. Hebrews goes into great detail to state this, "about the Son".
In speaking of the angels he says,
“He makes his angels spirits,
and his servants flames of fire.”
But about the Son he says,
“Your throne, O God, will last for ever and ever;
a scepter of justice will be the scepter of your kingdom.
You have loved righteousness and hated wickedness;
therefore God, your God, has set you above your companions
by anointing you with the oil of joy.”
The name Jesus inherited from the Father is Mighty God.
You have overlooked the Spirit of God. I think the Spirit of God was there with one of Gods Angels in that burning bush.
This is cohesive with Hebrews 1
The Son is the image of the invisible God, the firstborn over all creation. 16 For in him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things have been created through him and
for him. 17
He is before all things, and in him all things hold together. 18 And he is the head of the body, the church; he is the beginning and the firstborn from among the dead, so that
in everything he might have the supremacy. 19 For God was pleased to have all his fullness dwell in him, 20 and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross.
ONENESS
Jesus replied, "Anyone who loves me will obey my teaching. My Father will love them, and
we will come to them and make
our home with them