Greetings, DrMerlot, and welcome.

<<I am now thinking that I would like to change career direction in mid-life. I would like to use my IRA money for my higher education expenses. Lets say I want to get an MBA in finance and avoid the 10% excise tax. What can I consider as room and board? Can my mortgage
and food expenses count if I live at home and commute to a State University?>>

No, you may not count those expenses as room and board. Room and board is limited to:
a.The school's posted room and board charge for students living on campus, or b.$2,500 each year for students living off campus and not at home.

<< If I already have a graduate degree, does that make me ineligible for another advanced degree in another field? Is there an upper limit as to what I can take out of the IRA if I can go on for more education? >>

Obtaining another graduate degree will not preclude you from taking a withdrawal from your IRA for that expense. And there is no upper limit on what you can take penalty-free. However, you may not take more than the annual education expense without incurring the ten percent penalty on the excess taken that year.

Regards…..Pixy