You can't beat the price, either, or the interest rate on deposits.

It's an estimated cash on cash return given current rental rates subtract expenses assuming 7% interest rate, 10% management fee, 5% repairs, 5% capex and other expenses like mortgage, insurance, tax. it's a estimate to tell you what properties to analyze vs ignoreyou can see the are pockets of negative returns as well as pockets of positive return. this is to supplement the data @Devin Conley provided

For any of these real estate funds that have guaranteed rates of returns for set periods I would want to understand how my investment is secured.

A 4 bedroom would have you competing with larger condos or townhouses with pools, a much lower rate of return. 

What cap rate is the selling asking?

* Does it significantly affect rental demand, vacancy rates, or rents?

Personally I would want to manage the rental myself at least in the beginning to make sure you get good ratings.

Should I price the land 2 times above market value and offer a low interest rateORPrice the land at current market and use a very high rate?

FInd a good old school General Contractor and forget these engineers.

Default rate - as you scale you will have a 10% default rate on loans.