A friend and I were puzzled to see "malted barley flour" listed as an ingredient in all-purpose flour and bread flour but not cake flour or any sort of whole-wheat flour. This was the case for every flour brand I checked (two "store" brands and three advertised brands - all U.S. brands). My friend said that would never happen in Hungary.  I looked over the detailed discussion on this site of different kinds of flour and protein/gluten percentages, hard wheat vs. soft wheat, etc., but no mention of malted barley flour.  So I am curious:   What exactly is malted barley flour? What function does it serve? About how much of it is included? (like 30%? or more like 1%?) Do any other countries besides U.S. put this in their (wheat) flour?  
Yes, perfectly fine to freeze it. It will last approximately forever, frozen.  Related: How long can you keep chocolate in the freezer? 