Rud mentions 'Valentine' (pronounced Val-in-teen) is he referring to....

No. He's referring to the french science fiction comic book series "Valérian and Laureline" (Danish: "Linda og Valentin"), that he reads.

Nope, it's the Danish name of the cartoon character Valérian. He thinks Liva is his partner Linda (originally Laureline). That is also why he goes on about UFOs and such.