OK, I know this is way out there but. . .
Is there any legal obligation to spell things, especially names, phonetically (at least somewhat)? For instance, could someone say “My name is Jones, that’s spelled S-M-I-T-H.”
If someone tried to pull such a stunt in court, or when applying for legal licences could a judge order the person not to do it?
There’s no legal obligation to spell any particular way. After all, the legal documents all have your written name, no matter how it’s pronounced. The verbal form doesn’t matter to things like contracts and checks and so on.
I don’t even think a judge could say anything (legally binding) about such an inane stunt, at least not in the US. Picking a strange name is legal in the USA.
Probably no legal requirements–after all, Prince changed his name to that weird symbol and seemed to do all right. (I read a story where a reporter asked one of Prince’s entourage how to pronounce it, and was told something like “any way you’d like.” I instantly knew that the correct pronunciation was “butthole.”)
Plenty of practical problems involved in such a stunt. And if led to fraud, or possibly other types of problems for those trying to deal with the person who did it, there would be legal proscriptions and/or consequences.
Well, if you’re trying to do it with intent to defraud, it’s illegal. And if you try to argue your way out of some obligation because of the trick, you’ll quickly find the courts extremely unsympathetic.
You’re absolutely right, that is way out there.
IMHO (IANAL) the pronunciation of a name doesn’t matter for legal purposes, it’s how it spelled when written down.
In one of his novels, Heinlein makes reference to a person whose name was spelled “Zautinsky”, but pronounced as “Jones”. Something to do with a will…
Monty Python fans will recognize that the name “Raymond Luxury-Yacht” is correctly pronounced “Throat Warbler Mangrove.”
Not really. You can sign your name several different ways and as long as it is clear it is you and there is no intent to defraud it is fine. I know a will will be valid whether it is signed by “Margaret Meade”, “Margaret H. Mead” or “aunt Peggy”. As long as the person is clearly and unequivocally identified the document is fine. Many attempts by defendants to get indictments dismissed on the grounds that their names were mispelled have been dismissed by the judges. If it is clear you are the man, then the spelling is secondary.
Also from my experience in housing programs and loan, banks and government institutions will write up affidavits where they will write your name in many, many ways.
For example, a friend of mine was asked to signed an affidavit in which his name was spelled as follows:
Erik Wright
Erick Wright
Erich Wright
Eric Wright
Erik Right
Erick Right
etc.
etc.
So however he spelled his name, it was his loan.
XicanoreX
The first thing I did after reading the OP was a text-search of the page for the word “throat.” Thank you for not letting me down. 
Of course, Prince changed his name to a symbol for business reasons. Warner Bros had the legal right to Prince music, Mr. Nelson was interested in making some money for himself.