I'm currently researching the market, trying to get an understanding as to where these different areas are located in the cities.Any indication is welcome!

But there's no body of case law indicating that to be a concern.

One of the head architects on the construction of the new business district/town center is Hickok Cole, making their recent 75,000 square feet of the new Virginia Tech office space acquisition very indicative of the seriousness of these development plans.

There was no market data indicating there was a market for $3K 3 BR rentals but that was merely because nobody ever supplied the market with the inventory.

Since this is a long-term investment, it’s still important to prioritize areas with strong population growth and a healthy job market—both are great indicators of long-term potential.

That indicates price is the problem.

Since you have no contract, there is nothing that says you do not have to pay if you are not satisfied, and your spreadsheet would seem to indicate you owe him the money.Similarly, since you paid him for previous work on the spreadsheet, and the spreadsheet shows you owe him for additional work, your argument is not very strong.

We keep seeing conflicting views but my personal experience with buyers indicates that the outlook is positive.   

As others noted, most municipalities issue future zoning maps which indicate the direction the local planning commission or equivalent wants to take their zoning and if your plans are consistent, that's generally a good indication as well. 

This is often easier in lower tier markets where the appraisals are not indicative of how the property would sell in an arms length transaction.The other risk you run is over extension.