Yep,usually a Ph.D in Business requires the candidate to be able to handle math with ease,especially Probability and Statistics. To do that, of course Mathematical Analysis and Advanced Mathematics are a must. Yet for business major students, Mathematical Analysis and Advanced Mathematics are only partially offered as Calculus and Linear Algebra, which are quite basic.
It's possible. My friend graduated one year ago and he did not got any full time job. However, he managed to stayed in US working as a paid intern for one year.
I honestly dont know how he did it. He did not earn much, but enough for living on his own.