Some people just use "zie" instead of "they" as a gender-neutral pronoun. Personally, I find "they" to sound more neutral. "Zie," as you mentioned has connotations of being specifically genderqueer; plus, it is not really a part of day to day language so it sticks out.

I usually default to gender-neutral pronouns unless it is obvious the person prefers other wise. And as princess, says it is away to obscure the person's identity so as to make what you are saying sound more general and less directed at a certain person.

"I obviously do NOT believe that using "zie" to refer to a binary-identified cis-individual has anywhere near the emotional impact it does on a binary-identified trans-individual." - This I agree with strongly.