Has anybody ever used “Max Spann Real Estate & Auction Co“ to buy properties for investment purposes?

You don't NEED a realtor to complete a residential real estate transaction although they can certainly be helpful - it just depends on your comfort level with owning all the steps yourself.   

Personally i dont want to do engineering forever, every upper level engineer i know works crazy hours and the stress level seems high.Good luck in engineering and real estate.

It depends heavily on your personal comfort level with making managed risks like this.

It depends on your comfort level.

Also, any of the rent to purchase ratios are just general rule of thumbs too. 1%, 1.5%, etc... that is again going to be completely property and rent level dependent just as the 50% rule is.

None-the-less, I think it would depend on what level of involvement you want to have.

My husband is a 1099 employee and usually claims a lot of itemized deductions so we don't pay as much in taxes.

What would be your advice on the levels of risk-reward grading of the following Real Estate categories?

I am looking to get financing on a 3 acre plot of land and build a small house in Colorado.