Can the new apple tv remote (Siri remote 2nd gen) control a standalone audio box via IR? And display a diashow when starting?

I'm contemplating buying the new Apple TV because my 2019 LG OLED can not stream high bitrate PLEX content over the ethernet port buffer-free and I want to avoid using the TV's WiFi and want to take some work off the internal TV CPU as well to make the TV last as long as possible and outsource everything to the ATV basically.

What got me excited is the following from the spec list of the new ATV 4K: "Control your TV or receiver via IR or CEC.*3". That footnote 3 being: "Powering on and off, switching input to Apple TV, controlling volume, and mute."

My audio goes analog via RCA jacks to an audio amp (Pro-Ject Pre Box S), that I control with one of those little cheap IR remotes (volume up & down). So CEC is not possible, but can I program the Apple TV remote to control that Amp via IR? That would be awesome as I could get rid of that cheap IR remote.

And a bonus question: Since I don't have actual TV reception, my TV always defaults to an ugly "check cable connection" screen after booting. If I were to get the ATV, would it boot to the main ATV menu when switching on the socket or could I also specify it to display some iCloud or locally stored photos when booting up?

TIA!