Hi Mandeep,The 100 sq. ft. of exclusive landlord space could be utilized in a Business Use of Home deduction on your personal tax return, accounting for 10% of your home expenses.

The purpose of course, is to save for retirement in either a deferred or tax free account. 

Look up local ordinances, laws, taxes, and insurance.

As to your primary residence exemption, if you don't live there and you claim primary residence exemption that would be tax fraud.

That will provide you with confidence knowing there are no taxes owned or unpaid liens.I have worked with Lucia Rushton in DFW multiple times who can great agent and it is well worth using her to avoid painful mistakes! 

A 50 unit building has one property tax bill and one insurance bill.

If so, does Idaho state income tax impact my Federal tax return at all (i.e. taxed twice?)

Appreciation, tax benefits could make it a sound, long term investment.

One thing you might also consider when choosing a place to invest out of state is; After you have property there you can visit the area for business and a have tax write off.

No income tax if it’s your primary residence and you own for two years.