What cam?
Spring? Yes, get the springs that come with the cam from the same manufacturer of the cam. The cam company took the time to create a spring to work with the cam.
Low spring pressure applies else where, not with these cams.
The deal with the headers warning is that the coating can get baked off due to the extra heat created during break in. If the header is just simply painted, no worries. If it has a ceramic or other type coating, use old manifolds or headers instead.