As soon as we took over she reduced the amount she was paying by 10% because she thought she was acting as the property manager now.  

Demand generally as a rule slacks off in the winter months, thus demand shrinks to some degree thus prices get reduced or sellers will generally accept less during this time of year.

I Want control on who is living there and the metrics I use to screen them but the best return on my investment and reduce overturn and damage to property. 

A lot of that is fueled by low cost debt.  

To reduce a little bit of my risk of getting bad tenants in the form of non payment, I would require two options:  A.) two month's rent ($700) up front or  B.) one month's rent ($350) with parent co-sign the Renting agreementThis particular apartment complex is highly sort after and the $350 per month rate is the lowest rate over the past 3 years.

The book Zillow talks mentions that male agents start lower, but reduce prices less. 

The 1st option would allow me to close on a duplex within the next 30 days and reduce my mortgage to $150.00 per month as the other side is currently rented for $1200.00.  

I am not a marriage councilor, a quick cash business, bank, humane society etc etc.I say all this to make the point------- Have a lease    Stick to it       Be firm     Don't make concessions     It's an agreement/contract       Hold them accountable     They are an adult      Don't accept a reduced rent because you feel bad for them - this is a business not a charity.Because you accepted some sort of payment of rent you may not be able to count this month as violating the lease on the rent amount - you will have to check state and local laws.On the pet provision that was broken, you should be able to give them a 30 day vacate notice for violating the lease agreement.

To save, I would suggest opening a separate bank account, have some of your earnings go directly there, and add to it as you can further reduce your living expenses.  

But, I have a feeling that if you really dug into the numbers, you'd find that you're just creating an unwieldy infrastructure that's going to hinder your growth and reduce customer satisfaction.Again, just my $.02...