In summary:
No more henchmen as troops, not as primary, not even with Coteaz "Lord of Formosa" gone.
Valkyries updated to AM spec
Can take Santic, but no mention of a rule preventing even Coteaz getting perils on any double...RAW he's faction Inquisition and not GK so....
Though this isn't a nerf as such there's no mention of taking multiple detachments....so it would seem one could effectively pick limitless single HQs to attach to every imperial squad....I guess it depends on interpretation of rule book.
Only none nerf was the Chimera, though I suspect that was an oversight....