We can take a super Techpriest if we want. Iron Priest is not a separate entry, just a wargear loadout for a Techmarine. Go for it!
Apothecary sucks, I fully agree.
Commanding Oratory looks good though. For 2 CPs you can chant a Litany outside of the Command phase and it automatically goes off. Great if you have brought a priest in from Reserve and really need Canticle of Hate to go off. Easily worth the 2CPs, no need to upgrade to Master of Sanctity.
Sanguinius stood up, stretching his wings to their full extent. He flexed his hands. "I need no blade".
It was as though Sanguinius gleamed with pale light, his face white, eyes becoming blood-red, surrounded by the golden crown of flowing hair. Guilliman had witnessed glimpses of of his brother's wrath before, but had never seen the true Blood Angel unleashed. Sanguinius surged forward on alabaster wings, half a meter from the floor, whiteness streaming from him like flames.