Yes, it works without problem. If you want to connect a TV box and another device to the sound bar, I advise you to order a HDMI mutliplug with a swtich (cheap on "wish" websites...)

The best option is TV -> optical sound bar. Everything connected to the TV will be output on the sound bar (game console, tv box, dvd ... ...)

Yes it works, I have ARC but I don't use it. I have all connected to the TV and I pass the sound through the optical cable from the TV to the bar.
The sound response for me is much better.