ARC and optical audio are the same thing.
Be aware that HDMI typically travels from source to destination. So, your A/V receiver is typically the source. ARC merely allows that HDMI cable to be used in reverse to send audio into the receiver. It is quite common to completely ignore ARC and just use optical audio output from the TV to feed an A/V receiver, and that's perfectly acceptable. Quality is typically the same as what standard ARC offers. eARC offers higher quality audio, but both the receiver and the TV would need to support eARC connectivity. Not sure your does, it would be labeled eARC on both devices.
Another option is to not use the TV speakers for anything. To always use the A/V receiver. Get a good universal remote control, and hook all your sources up to the A/V receiver. That's what I do in my house. Roku, AppleTV, Cable Box, media player, etc. all go into my Denon (or Yamaha) and when I push a button on the remote, it turns on the proper gear and the remote controls that device properly every single time. It's easy enough to do with a good remote, and solves so many ease of use issues that people have. You do want a good remote and you want to ensure your family sticks with that universal remote.
My kids, wife, and family that visits quickly figures out how to use the remote for basic control of things. It's a much better way to go. Also, you are always using your good speakers and good sound and good gear for everything, which is why you paid for all of it!
