Thanks for your work and your advices.
But I'm sad to say that I'm back to my my Mac Mini (1,1) 2,1 (has to be said, thanks again too for this trick
) with CrystalHD.
Too much weird side effects, like crappy sound with headphone jack and HK SoundSticks II, old Samsung with sadly known capgate that didn't output correctly sound from HDMI, no easy to find mini-pcie card with WiFi/BT support, strange suspend/wake behavior, no CIR support... The Intel 7260 was only used for bluetooth but still non-stable behavior.
My plan was to recycle my MacMini in to a pfsense box and the NUC to a Mac media center : MacMini stayed the media center and the NUC became the FW appliance.
I'll keep an eye on your topic but for the months to come, I'll stay with my current configuration.
EDIT: I'm my research for a viable solution for the remote part of my project, I've found this
https://www.pulse-eight.com/p/154/intel-nuc-hdmi-cec-adapter. And they do purpose a driver for Mac OS X. Maybe a alternative solution?