Is singing a taunt regarding one ethnicity being more favourable (implied by the tone of the song better) than another one should they be put up for choice racist or not?
Yes. End of. You came in the first instance asking me if signing it was racist, you had your answer and decided I had not been addressing your suggestion of singing but saying "So saying "I'd rather be Scottish than Irish" a sentence that isn't abusing either nationality, but is more positive to one than the other is racist." <- (not put as a question you drew this statement from what you had gathered from my answer specifically regarding singing it - when that content wasn't there).