A:AnswerI haven't done it but you can manually adj speaker volume levels, see user manual PG 70. No balance knob, use setup menu, speaker. +/- .5 db ea spkr.
A:AnswerNo, video cannot be input through USB.
See page 101 of the owner's manual for supported USB devices and file formats:
https://usa.yamaha.com/files/download/other_assets/1/1161601/web_AV17-0087_RX-V385_om_UCABGLFP_En_A0.pdf
HDMI ARC (Audio Return Channel) is for AUDIO INPUT from a TV that supports HDMI ARC output. ARC is not video output. HDMI sends video and audio output from the receiver to the TV, or HDMI ARC receives audio input from the TV tuner to the receiver when the TV tuner input is selected on the TV. See page 21 of the owner's manual, although there is a technical error. ARC does not simultaneously send video to the TV and receive audio from the TV.
Best Buy should answer your questions. You shouldn't expect other Best Buy customer's to answer your questions. I don't trust Best Buy or their customers. I look up answers to my questions on the manufacturer's web site.
A:AnswerIt comes with a microphone to determine speaker sound levels so yes. If you are talking about Karaoke, then it depends on the microphone's output.
