Unless severe corrosion is evident, the edge does not have to be "good," as honing will make it good.
That's just plain not true.
I can almost completely agree with this, but I do have several razors with cracks that honed up and shave just fine. As long as the blade doesn't scratch the strop, it's unlikely to scratch your face. However, many would disagree with me about this and believe that no razor is worth the risk to your face.
Again, not true. As with chips, the right tools and techniques can allow for the quick correction of a frown. It takes minutes, not hours. Regarding the spine, there is no need to remove any steel from the spine during the removal of the frown unless the spine needs to be corrected.