It produces beautiful expense reports by property.  

They are very expensive. 

I would say cut your expenses down to the bare minimum and pay off the student debt.

I avoid the rough areas and the expensive areas generally don't provide a good return. 

More employed people with lower expenses means they have more wiggle room to rent a nicer place.Sara also mentioned looking at whether or not new businesses or franchises have opened nearby, which is a great tip if you are looking for up-and-coming neighborhoods.

b) deposit back (though they consented to having us either sell/rent and deposit covered the properties expenses to get sold/rented...closing and other costs to sell exceeded deposit)?

Their only interest is in making money at any expense.

If you are withholding any portion of the deposit, you have to share receipts for the expense. 

Generally, if the tenant is willing to accept $500 or $1,000 and save you the expense of filing for an eviction, that is a better option and also serves to preserve the condition of the property. 

I'm assuming "a couple hundred per month" in expenses for NNN, but I'm just at the start of really doing any DD and this is the first commercial property I'm digging into.