Sorry,it can not support CEC,ARC and eARC.
Please you set audio out of your hdmi input source with source mode/auto mode,then set audio channel with 7.1CH of audio extractor,You will get Dolby-True HD/Dolby atmos.
Yes,HDMI AUDIO Out could connect with HDMI INPUT of eARC soundbar/AVR/Amplifier,But it prohibit with HDMI eARC INPUT of eARC soundbar,Such as some sonos earc soundbar
Yes,it support 1080P@120Hz,4K@24/30/60Hz
Yes, this hdmi splitter 4k@60hz will allows you watch 4K@60hz tv in your bedroom and 1080p tv in living room at the same time.