I couldn’t retrieve a transcript for that YouTube video (subtitles/transcript appear to be unavailable).
Here’s what I can confirm from the video metadata:
Title: “Smokie - Living Next Door to Alice (Ein Kessel Buntes 25.12.1977)”
Good question “Alice” is almost certainly a reference to the thread title you mentioned earlier: “Smokie - Living Next Door to Alice”—it literally uses Alice in the title, so people bring it up.
On the forum side, I also see an Alice 17 user profile in the user data, but the “who the F is Alice?” vibe fits better with the song/title reference than a specific person.