Dual Use Property - Possible Deductions

Hi,

I have the following scenario:

My wife's family owns a property in Vermont with two buildings and ~100 acres of land.

 

Two questions:

1) While my mother-in-law is the owner, my wife and I pay for all the expenses and also receive income from renting out one of the two buildings on AirBnb and month-by-month.

--> Since we have to report the income, can we also claim any deductions, e.g. maintenance and property management fees we pay? OR do we need to own the property to do that?

 

2) There are two buildings on the property, one is for personal/family use while the other is only used commercially, i.e. rented on AirBnB or month-by-month. There is no personal use of that second building.

--> Can we and if so what is the correct way, split and deduct expenses such as property taxes or insurance between the two buildings?

 

Thank you