More people use guns to kill themselves than to kill others.
When someone transitions you should refer to them by their new name both in the present and with references back in time.
A quick comeback is usually meant as license to be mean.
Please Mr. Trump: Say what you mean. Mean what you say.
You do not need to be female to be offended.
Calling a trans person by their former name is referred to as "deadnaming" and is considered highly offensive to most trans people I know.