By your given definition of "slur", neither "management" nor "cissy" are slurs (except in the sense of "cissy" as a variant spelling of the slur "sissy").

I'd say "white" is no more or less malleable than the others. "Male" has multiple, mostly-overlapping definitions; by extension, "heterosexual" and "cisgender" are likewise flexible, though "heterosexual" has additional flexibility. While the concept of "white" is completely ungrounded in base reality, as a cultural term (a description of how racists categorise people, and of who's affected by the consequences) it's relatively stable: the definition in Western Europe is completely different to the definition in North America, and the boundaries have shifted over the centuries, but contemporary racists in a given racism-domain seem to agree with each other.