To answer the schlong question, I always figured that the way the skin thing worked was that his skin would fall off, and everything but his skeleton would be this translucent green glow, like this.

[img=http://static.comicvine.com/uploads/original/6/68616/1626607-38.jpg]

So it would only be glowing green as opposed to the sick shit metro saw.
For your second question, no, its not. Jacob is entirely unaffected by outside radiation, and aside from the skin thing, he's undamaged from his own. However, because of the nature of his powers I'm considering making him sterile.