My offers are based on market analysis, and calculated based on the maximum number I can offer and still make either my desired cf and/or profit on that property. 

Your gain will be Sales price less sales expenses(Commissions, closing costs) less Adjusted basis.Your Adjusted basis will be Purchase Price plus Improvements less accumulated depreciation.Depending on how you categorized the improvements / furnishings will determine how you will calculate your gain.If you already took depreciation / expenses for the furnishings, you can't also count it towards basis to reduce your gain.Best of luck.

They provide a "resident score" which is their proprietary calculation they've come up with similar to a credit score but apparently it's more robust and comprehensive.

Many places followed this with some excluding babies from the calculation.

Moral of the story investor used the calculator and beat me down and well I will not discuss how much money I'm loosing on this project. 

This is calculating a return rate of 8% (inflation taken into account).I might be a little bit more risk averse.

Alternatively there are also asset based lenders that do not require DSCR calculation or income verification, that can be less costly than hard money, and fully amortizing.

Per this NY Times article, the average American knows around 600 people.https://www.nytimes.com/2013/02/19/science/the-average-american-knows-how-many-people.html#:~:text=The%20average%20American%20knows%20about,do%20you%20know%20named%20Kevin%3FPer the US Census Bureau, the average American moves 11.7 time in their life, which based upon an approximate lifespan of 84 years, works out to be about every 7 years.https://www.census.gov/topics/population/migration/guidance/calculating-migration-expectancy.html#:~:text=Using%202007%20ACS%20data%2C%20it,one%20move%20per%20single%20yearSo, if the average American knows 600 people and they each move about every 7 years, that means that the average American knows around 85 people that move in any given year.How many of those moves do you want to be involved in?

When you turn a personal residence into a rental, you want to make sure you calculate your basis properly.Your basis will be purchase price + improvements made to the house since time of purchase(Assuming the FMV at time of conversion is atleast this amount).Best of luck!

You can read books about estimating and find calculators online, but the best way is just to do a couple projects and see how well you are doing.