Ultimately, the investor would be paying $320k to purchase the house.  

When I first got on here, I read BP's Ultimate Beginner's Guide to Real Estate Investing.

Of course, you need to read The Ultimate Beginners Guide to REI here on BPIf you haven’t already, please read/listen to these books ASAP!

Correct me if I'm wrong but I took your post to mean, tracking all major things that incorporate, or effect NOI is wise because ultimately a large component on your IRR strategy will be based off the exit and or refinance, which obviously is the factor that you as an investor can control when considering the capitalized valuation of the investment.  

Then, download the BiggerPockets Ultimate Beginner's Guide and start reading some more!!

Although currently I do not own or manage any type of investment properties, I am hoping to begin to actually research the many details of what it takes to purchase various properties and ultimately become successful in the business. 

This is ultimately a people business, so if you are honest, open, direct, and organized when it comes to communicating with your Hard Money Lender, it will definitely improve your odds in obtaining a loan approval for your project.In summary, if you follow these 7 Steps, the Hard Money Lender will be able to quickly evaluate your project and hopefully Approve Your Loan!

Remember you are dealing with the dregs of society that primarily survive through criminal activities.

Bonus question: In general, when a home is damaged by tenant negligence or a simple accident (ie towel bar is accidentally ripped out leaving a hole in dry wall) , who is ultimately responsible for paying to fix that repair?

In 2005-2008, I pulled all of the 180k in equity out and put it into a business that ultimately failed, leaving me with a property I owed more on than what it was worth.