Andrew You have to factor things like:- vacancy- property management- repairs and maintenance- replacement reservesin addition to the usual PITIA (Principal, interest, taxes, insurance and assessment).

• Addition costs (additional bedroom, bathroom, etc.) per square foot?

Additional info: $5000 profit for me and selling to a flipper with a $20k minimum profit.

In addition, I am currently studying for my CPA and I am considering what area I plan to be a specialist in.

If you are wanting to add more properties, it probably makes sense to pay the regular payment and save additional cash for other opportunities.  

An all cash, no loan transaction).For this reason, I calculate both cash on cash vs. total yearly return on my out of pocket money (which includes the down payment).Also note that usually you pay the first month of the mortgage in addition to the down payment, plus the whole of the insurance and (some) taxes at closing.

Land Real Estate Investor who employs a suite of radical and innovative acquisition, negotiation, marketing, and disposition tactics throughout the United States to purchase and sell vacant land real estate for profit.  

Not working more hours than that (750) for any other income.Then I realized that when managing multiple properties there are additional rules and to get around it one can permanently elect to treat them as one but then it could fire back when selling one of the properties... and then I am lost.Can you recommend prescriptive guidance on it?

Happy to provide additional information as needed.

Job growth, population growth, low unemployment, good schools, diversified employment, household income growth, all of those are available to you from free sources they will tell you where the good spots are.