Like a calculator to simulate this strategy (https://www.biggerpockets.com/forums/61/topics/795487-retire...), maybe showing how much equity could be pulled out of which property when, whether the portfolio would still cash flow, etc.

A simulator/game could really help with that.

Credit Karma has a fantastic "score simulator" tool that you can use to project credit score changes (paying off balances, opening a new card, using an old card that has not been used in some time, just paying your bills on time for 6 or 12 months).

If credit is the issue, talk with your lender to run a credit simulation to see what actionable steps you can take to improve it.  

@Nate O.To spark your son's interest in real estate, begin by teaching him financial basics and slowly introduce real estate concepts through hands-on experiences like simulations, shadowing, or DIY projects.

My conclusion is that the Vertex42 spreadsheet is just fine and it was very easy to simulate the situation. 

I have many years of construction experience and have also done a fix and flip, in addition to ground up construction, as well as 10 years of entrepreneurial experience running a paddle board rental company, and advancing science through developing theoretical methods for efficient large scale simulations...I guess my problem is I can't seem to figure out how to find the money to do more projects, which is why I've been trying to sell my house.

Until then working through simulations until we happen upon a deal that works for us.

Pls let me know where you disagree fundamentally.Even though I haven’t run the numbers in full detail, I noticed a flaw in the AIO simulator which seems extremely misleading.

They usually have simulators that will tell you how much you need to pay off on a particular debt to accomplish a particular point gain on your credit rating.