The primary metric on this puzzle was a delight to grapple with.  We were able to rule out the theoretical necessity of the Glyph of Duplication quickly enough, but it took longer for us to understand that that meant only one atom per input could be made useful.  Because the salt cannot form bonds, it must always piggy back a fire atom when added to the waste chain.   

But as for the other metrics, the solution title encapsulates our opinion.  Our only concession to the secondary metric is the fire-grab-free wiggly waste chain.  We made little effort to figure out an indirect construction method that would avoid fire grabs.  We believe that zero should be possible, and greatly hope that some enterprising alchemist can show us some examples!