She asked me about it, so I told her I know they have a two bed room voucher, so she put one of the bedroom as home office room. 

This protects you if you have to fire them.2) Pest treatments would depend on the location.

The house is 2 Bed 2bath 1300sqft.

pest control?

Seems like a nice bed of cash coming in to use as a launch point - plus minimal cash out the door on initial purchase.  

He paid for common area access, built a bed in his Land Cruiser, pocketed the rent but we had agreement on what the pocketed money could be spent on (seeing we were paying the rent). 

There is no bathtub, and it is only a one-bed one-bath 680sqft unit so I'm not sure if I'm overthinking this.

Electricity alone on a 2 bed is usually around $200-250.  

And the size of the duplex and bed/baths depends on the size of lot, location, and what we best feel would rent best and all the other factors. 

Income Late fee Gross rent Expenses Advertising Cleaning Gardening/lawn mowing Insurance Interest on loan(s) property tax Legal expenses Pest control Property agent fees/commission Repairs and maintenance Water charges Electric Bill Total expenses Net rental income or (loss)