After 2 months going back and forth with them, they finally ended up paying 50% of the $9000 bill.

I felt unprepared.2) PML- I did not have any leads or proposal packet prepared to present3) I couldn't figure out how I'd pay for the monthly costs to HML

Cost segregation utilizes the MACRS approach.

hi all i am a new landlord and got my first rental property. tenants moved in in September and October. the first month was fine but when December hit it got extremely cold and the heating is electric. due to poor insulation in the home that we did not know about the heat has to be turned very high up to keep the home warm, however since everything is electric it is causing the electric bill to be $800. the utilities are the tenants responsibility. however because of this one of the tenants has been extremely non compliant with paying rent.

I don't have a garage or any parking so that could hurt the monthly rental appeal. 

So, I would expect to lose 3 months rent maybe more.

Here's an article with FAQs including the cost of a study.

WHAT IS A COST SEGREGATION STUDY?

I would strongly consider building equity to make a stronger down payment and further decrease your monthly cost. 

All properties are eligible for a cost segregation study as long as they are investment properties.