Iain's name was at the beginning of the sentence.
Iain is a name that is not lenited when being addressed. If it were, for example, Flòraidh, would the sentence be: "A Fhlòraidg, ciamar a tha thu?" I am not sure, but I don't recall that sentence configuration being used.
Hi I may be not quite right but I think dòigheil is fine and gu dòigheil it'll be literally finely ( if such a word existed) since gu makes the advervial form( like math is good and gu math, well). Duo is translating gu dòigheil as really well but gu is not "really" but a particle used to make the advervial form. I hope this helps. I used to think gu was really until they kindly explained it in another post. Please correct me if Im wrong.