Calcium chloride as substitute for sodium chloride
This is an interesting idea.  I have heard of using some potassium chloride to make reduced sodium pickles, but never calcium chloride.  So I did some googling:

Here is a PDF from OragonState that says you can use potassium chloride it for quick pickles, but not brined pickles. I'm assuming calcium chloride can technically do the same, but I don't know what the conversion ratio from table salt is.  They say:


  Reduced-sodium salts (such as potassium chloride) may be used in quick
  pickle recipes. However, the pickles may have a slightly different
  taste.  Don't use reduced-sodium salt in brined pickles or sauerkraut -
  these products need a specific amount of sodium to control bacterial
  growth and to give a firm texture.


Also, I found several recipes for "no salt pickles" that are just brined with pickling spices with no salt at all.

As for smoking fish: it should work but I would be VERY CAREFUL.  Calcium chloride is extremely hygroscopic.  It is used as an industrial desiccant.  You may end up with petrified fish.