A: yes, its 100% natural wood and not treated whit any chemicals.
A: Yes, but you need to apply linseed oil to protect the wood for your raised bed. I started using this wood last year for my raised beds and it has done well.
A: The edges are straight. A little sanding would do the trick if round is what your looking for.
A: Yes, this kiln dried Spruce, Pine or Fir lumber is adequate for building wooden shipping containers...Check with the shipping company / carrier for their regulations on materials used, there could be an industry standard or several different regulations per shipping company...Also all shipping companies might have a regulation regarding fire proof or fire retardant materials...