It actually is, since it diminishes the fact that he is truly and fully God. His humanity is not merely an insertion into his divinity, but he became as fully human in every way as he was fully divine in every way. He wasn't God with a human skin or a human that had God inserted into him, or some other kind of admixture, but was from his conception fully human and fully God.
Not in my view. God dug into the dirt with His hands to create man, while speaking all other life into existence. Did God become diminished when He got His hands dirty, when He could have spoke man into existence as well?
One of the wonders of God is how He is willing to reduce Himself to interact with us. He got His hands dirty to create us. He lived in earthly materials in order to dwell with us. God has often reduced His standards so we can have a bar to meet. God indwelled in a human body that got battered and bruised to for us. God is with us, wherever we are. He is in the prisons, the hospice, with the orphan and starving. It has always been the case the God reduced Himself to meet us on our level.
Creating a human body and inhabiting it, making it His own, is not beneath God at all. God is love.