Can you use both RCA and XLR interconnects into the amplifier?

I would be careful. My Parasound A23+ has both inputs and a switch but I don't think they're isolated. When I accidentally put the switch in the wrong position, sound still comes through but a different level. Yours may be different.

Do you have a switch to select which input you are listening to? If so, then yes. I used the exact same setup you are discussing with the tech on several amps. On one amp I had to install a selector switch myself since it had both RCA and XLR inputs but no say to switch. Both were live inputs at all times, so you couldn’t even leave wires attahed to the one you weren’t using.

So if this is your situation, a tech can install a selector switch.

Jerry

PS  you'll need to set the volume at the same level every time for your AV reciever,  It will then set it's internal levels.  An HT Bypass will use max volume setting.  This is error likely as eventually you will switch back to music and forget to trurn it down.  If you can use 1200 on the knob or if you have numbers, pick one you like that is fairly loud.  You want plenty of volume for the loud parts and you don't want the HT reciever to have to max it it's gain.  Best of luck

You should be fine.Input switching keeps everything separate.