Pet names are very intimate and rarely gendered. I often refer to my partner as poppet - go ahead and guess their gender.
In terms of work acquaintances I think your question is even weirder. Please don't call your coworkers babe or hunk - names are nice and you should default to using them unless they offer up a nickname and both of you are comfortable with them.
If I’m giving a coworker a nickname, it is usually some riff off of their real name that I know they don’t mind. This should be asked directly after creating it, and not just assumed. Most work friends won’t mind a humorous alternate name that is deployed sparingly and in private.
Maybe but some people may not be comfortable voicing an objection - please be very careful. It's usually best to only adopt a nickname if it's offered.