I would probably do hymns under music appreciation, while having a second credit over 4 years for kids who play an instrument (for example my current 9th grader plays piano (including for church) and is learning guitar).
Picture study I would incorporate in a Fine Arts credit (we do a lot of art expression as well so instead of an Art History credit or some such we’ll do Art I, Art II, etc, and each year’s course will include art appreciation, museum visits, and producing art in a variety of mediums.
Nature study I’m not really worried about fitting in the transcript, though if we did a good bit of hiking for it we could count those hours towards P.E., and studying plants/animals/rocks/stars etc could go under science. Just thinking out loud here.