NO. Find someone your own age.
If the male to female transsexual is still legally male and not yet legally female then yes. You'd marry the same way a man and woman would as long as the other person is still legally male.
No.
The only way for him to marry his girlfriend is for her to be 18 and him to have parental consent or if she is under the age of 18 both would need parental consent. The male would have to be legally divorced from his parents otherwise.
Im not sure about the laws of Missouri per say, but if you legally become an adult through court then I would say yes it would be legal.
I sure hope not, what is up with people being gay. There are plenty of beautiful girls to marry.
Yes, at 18 you can legally enter into a marriage.
Yes. Pursuant to a 1994 decision of the New Zealand High Court, a woman wrongly born with male parts who has undergone corrective surgery to create the correct genitalia may afterwards legally marry a male in New Zealand.
Yes.
Yes.
No. Missouri requires that you be 18 to marry without parental consent.
Yes she can.
I believe you can with parent consent.