Hope this helps!
I'm not a lawyer, but....
The other "owner" generally can relinquish his/her ownership through a mechanism as simple as a quit claim deed, so long as they're willing to do so. Now, if that person's name is on the mortgage, he/she may not want to do so, but that's an avenue to explore with a real estate attorney.
Hope that helps.
There are legal and tax ramifications to how you take title. Be knowledgeable and don't do anything you don't understand.
That's an interesting question, I've never seen that before. I would think the title would be held as "single man" rather than joint tenants. In the cases I've encountered it normally is used for non-married individuals (mostly same sex partners), but sometimes family members that are purchasing together. I'd ask your mortgage broker if this is a lender/bank requirement.
I'd be interested to see what others have to say and if you find out more information. You quite never know what interesting factors will come up with any real estate transaction. It could be a leaky toilet on the day of close of escrow to this type of question that you posed.
Thanks for the question!