It's Mithalwen!
ARIEN: Butterflies? Confused heroine finds direction twice, and she's radiant.
2. He appears to die, classically perturbed.
NAMO: A troubled sound of pain gives him away.
4. Mutilate, seize ring, but lose an article? Such chaos! Is he really that violent, or just very powerful?
5. Find him in a rotating sauna.
Indeed so. Late 70's and early 80's British sitcom starring Wendy Craig as Ria, the heroine, and Geoffrey Palmer as her husband. I looked it up and I think it ran from 1978 to 1982.
(I have the earworm, too).
Regarding the earworm, apparently the theme tune was originally a Dolly Parton song.