AFAIK, you can't ship on most of the reputable services without insurance (and I probably wouldn't trust any which allowed you to). And yes, packing lists (better yet pictures) are essential! As is checking whether the insurance will actually cover replacement...
If by freight shipping, you mean container (well, part of, aka groupage shipment), and if by super slow, you mean 6-12 weeks, and if by slightly dodgy you mean do things occasionally "happen at sea," then yes, that's what I'm talking about! Runonsentence, you brought back images of the river boats on the Ucayali, replete with riberenos lounging in hammocks next to barrels of gasoline...