RE The Fish and Chip song...I don't actually have a problem with that because it's not branded and schools need to be a place of fun where children can relate to "the school experience" as well as somewhere to learn, so singing a silly song about fish and chips probably fosters a sense of "oneness" with the staff etc. There has to be a space for nonsense and fantasy, free from "shoulds" and the imposition of "teaching" for the children to develop a bond with the teacher and school.
About the silly poo instructions....I'd be having pretty much that conversation with her teacher Sam, but perhaps from the angle of trying to ascertain whether your daughter got the wrong impression from a comment (to give the teacher benefit of the doubt). Good luck....I have had similarly awkward conversations with teaching staff in teh past, so know how you feel!!!