Actually, the Hue Dimmers CAN be paired to the HE hub (and they work really well; I have a few of them paired to my HE Hub). You can setup Rule Manager (or Button Controller) to keep lights off when you press a button and reenable timings/motion when another button is pressed.
As for the Circadian lighting, there's an app for that: [Release] [App] Circadian Daylight (v0.80) (Port)
[EDIT]: Regarding Hue Scenes, those won't map over using the Heu Integration, however, you can recreate them using the Groups and Scenes app. Basically, it's a matter of shifting the values over from Hue to HE and letting HE control them.
