Your financing method is important, as interest rates will significantly impact your cash flow. 

I don't think its wise to refi since I'm locked into a great rate.

What is the interest rate ?

You will see higher returns through appreciation as the city is growing at a much faster rate. 

Double check the 6.75% 30 year fixed rate.

Some would argue in support of a neighborhood in close proximity to downtown Sacramento such as the homes off of Lighthouse Dr, others would want to attract families with elementary school children who prefer homes in Bridgeway Lakes near Bridgeway Island Elementary School due to it's higher Great Schools rating vs.

From cap rates and cash-on-cash returns to net operating income (NOI) and internal rate of return (IRR), how do these numbers help you understand their impact on investment decisions?

Rate is 7% 2.

Houston is a little expensive, especially when combined with current rates but there are some BRRRR deals that can work with decent ARVs...just as a quick example, here's a ranked list of properties by BRRRR in Houston - there's a few that potentially make sense but not a huge amount of choice.

U want your parents to talk to their CPA FIRST.. if they go the development route they are now ( depending on the amount of units) creating inventory.. which will be taxed at ordinary income rates ( very HIGH)if they just sell they can 1031  and move on to something else.. many times when you run the math consider the risks of a partnership.. the sale of the land is far better than thinking your going to make some profit..