and my responses:

so when are you gonna get a penis?
"my plans for bottom surgery aren't your business. when are you gonna get some tact and common sense?"
you realize that even if they sew a hot dog between your legs, you'll still be a girl, right?
"you know nothing about gender, anatomy, or sex changes. even if they put a brain in your head, you would still be ignorant, right?"
how can you be a "straight ftm?" you're female, you like girls. doesn't that make you a lesbian?
"no, because gender and sexuality aren't related. i was born a female, but i'm not a girl. i've always felt and identified as a guy, so i'm a guy. i like chicks, that makes me straight."
why did you spend 20 years as a girl if you always knew you were trans? why not start t sooner?
"i wanted to transition years ago, but my parents had medical control over what happened to my body. as most parents do, they worried i'd outgrow this 'phase.' by the time i was legal to transition without consent, i couldn't afford to do it on my own. doctor visits and hormones are expensive. just because i couldn't afford it, doesn't mean i didn't want it or try."
i'm gonna keep calling you your birth name, even after it's legally changed.
"okay, that's your prerogative. i can't force you to change. you're going to look ridiculous calling me a name no one else associates with me, but that's fine. i'll come up with a different name for you that doesn't match your gender, too. how's gerald?"
i'll start calling you "he" when you start shaving.
"since when does respecting my gender identity and using the pronouns i've asked you to have anything to do with my facial hair? is that what makes you a man? so bearded women are really men, and little boys are actually girls?"
you're not a man if you can't ejaculate.
this was said to me by a woman who's cheating on her impotent husband. "sperm doesn't make a man. an inability to cum has nothing to do with my feelings of gender identity. if you had a six year old son, would you keep him in a dress until he informed you that he'd ejaculated?"
you'll always just be a she-he/girlboy.
"i've always been a guy. that isn't gonna change. it doesn't depend on my anatomy. i didn't choose my body. your ignorance was a choice."
god makes no mistakes.
"i'm not a mistake, but use that logic on anyone else with a birth defect. if a child is born with a hole in his heart or a cleft lip, doesn't that count as a mistake? or if that's not god's fault, neither is this. they are NO different."
you were born a girl. stay that way.
"you were born open minded. stay that way."