Charlie: An ecclesiastical marriage does not necessary equate to a legal marriage under State law. So if a rabbi or priest performs a religious marriage, they are not necessarily purporting to have conducted a legal marriage that claims the parties are married under State law. Thus, performing a spiritual marriage in no way violates any statues prohibiting the performance of a marriage outside of State sanctioning, if the minister does not claim the ceremony connotes a legal marriage under State law.
The State does not, and cannot under the Constitution, regulate or preclude a religious ceremony or deed, including religious marriages. In fact, the rabbi performing the chupa v’kedushin does not even have to be authorized by the State to perform marriages, if he chooses not to seek such recognition.
Indeed, a few years ago the Federal Court in the State of Utah overturned Utah’s law against polygamy that, on the books, prohibited citizens from marrying multiple spouses under religious law without obtaining a State marriage license. (It was widely ignored by Fundamentalist Mormons for the last 100 years it was on the books until the Utah Attorney General charged one person a few years ago for violating that law, and he successfully defended himself by bringing the Constitutional challenge in Federal court.) It was overturned as an infringement of the First Amendment.
Btw, Charlie, on your other point you are also mistaken in asserting that judicial consent is rarely given to minors under 16 years of age to marry. In 2011 alone New York judges approved the marriages of a 14-year-old, a 15-year-old, another 15-year-old and another 15-year-old. In New Jersey between 1995 and 2012 178 marriages between ages 10 and 15 were approved by judges.