Alpha,
Show me how 'the fullness of the Diety' means anything other than 'all of God', therefore meaning 'God'. As for us being filled with the fullness of God, that seems to me to be exactly what He wants for His adopted children and co-heirs with Christ - that is, for those who will rule with Him in the Heavenly Kingdom. After all Christ did tell us to be perfect. How else could we? The only difference here I see is that Christ is the only begotten Son of God - that is, God Himself in human form. In Christ God fills Himself (His human self) with Himself. In us he fills our selves with Himself. Smaller vessels, we human selves, but filled with the same Life and Power.
Show me how Christ can be the 'head over every power and authority' and not be 'God'. After all, God is a power and an authority. If Christ is 'head over every power and authority' He must be over 'God' or He must be 'God', who in fact is head over every power and authority.
God bless,
jimmy