Frei really makes no sense – but like that word for happy, that is what it now means, and so be it.
I actually use shygetz (purposely pronounced that way as in Shygetz Aross, which clearly refers to lowlifes of Jewish origin) and shiksa as synonyms for hooligan and pritza – to describe Jews who have fallen to the point that they are abominations. “Er iz a rosho, a shygetz..” is how I describe, say, Moishe Aryeh Friedman.