I've considered using a Monte Carlo Simulation method to assign a probability to each variable ( building sq.ft, lot size, finish quality, garage type, time of year sold, etc., etc) in order to mathematically understand the risk/reward of a project and contributions of each variable to such.

I can tell by your verbiage and questions you are out of comfort zone with this.It's best to follow the advice of your CPA and Attorney.You could ask your tax pro and attorney about:I assume these are both self employed sole proprietorships, vs legal entities (LLC, S-Corp, Corp).If so, why not just DBA and just do the work of both under that name.Sometimes when you shut down (legally wind up) a company you have an unexpected tax hit.To anylize the possible (LARGE or small or nothing) tax consequences, your tax pro might have to do a mock tax return and simulate that happening (and you pay for it), that way you would know if and how much a tax hit closing up would cause.[1]  It's best to follow the advice of your CPA and Attorney.[2]  It's best to follow the advice of your CPA and Attorney.[3]  It's best to follow the advice of your CPA and Attorney.There is also the credit history of both businesses to consider, if they rely on credit, will the credit availability of one business be enough to do the business of both.I don't think anyone online can give you advice that will work out for you without the possibility of great risk.It's best to follow the advice of your CPA and Attorney.Good Luck!

Do simulations on different methods - turn keys, SFRs, BRRRR, etc.

This is to simulate the leach field already being wet or in use.Percolation test-   Then you fill to 6 inches every 30 minutes and measure the loss of water during that time.

Laminate flooring simulates wood with a photographic applique layer under a clear protective layer.

Yes of course, if you send every single person in the USA a letter, you are bound to get a deal or 2.But then what you should do is plot a graph between your expenses, vs profits, and you will see that the only time, your profits surpass your expenses is when you spend a small fortune on marketing.You can't simulate motivation, because motivation has to do with the mindset of someone.It is uniquely different from person to person.EXAMPLE:Someone that is stubborn never gives up, has an ego, in forclosure... will NEVER sell their house and they rather see the house go, to the bank than admitting defeat and sell at a discount.Someone that is passive doesn't take action, and is unmotivated, in foreclosure... could possibly contact you to sell their house.So what happens?

You can do a reasonable linoleum flooring and hard wood simulation in a C area but will want nice tile and actual hard wood flooring in an A district.  

avoid carpet. if you have god hardwood then finish it. vinyl planks that simulate wood look great and wear well.

I like using the credit score simulator tool on the credit karma website to understand what will happen to my credit if I do X or Y.

If you hate cleaning the appliances (I know I do), find someone who likes to earn a little $$$ more than they hate cleaning appliances and "simulate the local economy."