I will try to answer these:
All of the equipment is in the tv room, except for speakers in other rooms. The TV, denon receiver, control 4 device, switch, audio matrix and amp are together. All of the speakers are hardwired into the ceiling. The system also controls speakers in other locations, but no other TV's.
all sound is supposed to come out of the speaker system. The TV doesn't (and I guess shouldn't) play any sound.
I dont believe there is a video matrix, but there is an AMS8 audio matrix.
YouTube TV is running on a roku device. Its also not just youtube, but all of the apps on the roku.
The control 4 appears to generally still be in control of the system. I can still play audio in each individual zone including the main room where the TV is. I can also control the TV, change channels on youtube tv, and switch apps. All is just w/o sound.
I appreciate the help!