The following is an expert from an article on Brick Underground that explains it really well.Can I rent out bedrooms in my NYC townhouse to help pay my mortgage?"

You will need to maintain the property with repairs and eventually capital expenditures as well, plus rentals don't stay occupied 100% of the time and renters don't pay 100% of the time.

She asked if she could pay $100 per month extra towards the deposit .

If you’re running a hotel you should be paying hotel taxes. 2.7% is probably 1/4th of what hotels pay?

I've seen these releases in Southern California to be 90 days (With no guarantee of that short of a time) of locked accounts where the owner had issues paying the mortgage, insurance, taxes and operating expenses for the properties.

I'm trying to figure out a strategy on buying real estate from the seller on payments, adding value and reselling it for profit and thus, paying off the original seller.

I have the same question, but this issue is more complex when an investor has multiple investments in different states with federal passive losses carried forward from multiple states.I doubt that states intended to allow non-residents to not pay state income tax by offsetting state sourced income with non-state sourced passive losses.

They pay rent, but there are lots of other problems. 

My best advice would be to calculate how much you would need to spend on food and determine how that number relates to the amount of rent you are paying.

I pay him money but then he disappears for a week at a time and won’t return my calls.