I'd say my biggest question right now is how to get accurate numbers for when analyzing a deal (specifically insurance and rent) and what's the ideal percentage to use for variable costs?

And like JD pointed out, a tiny percentage of transactions are made using seller financing, and an even smaller percentage of those are done using subject to.

and the entire conventional wisdom of the 70% are there any people who don't really use it all and have found out their ways of making the numbers work Like adjusting the percentage based on the market. 

According to the article, around 5% of the properties are being bought by investment companies, leading to concerns that regular homebuyers are being priced out of the market.1) Do you think this could become a long-term issue, given that the current percentage of investor-bought properties is relatively small?

While the guarantee of income sounds great, it's only a percentage of the rent, typically up to 70% and the tenant has to pay the remainder.

A very small percentage do it an easier/softer way.

However, there will be a segment with a high percentage of reliable people.

What percentage of those who joined would you say reached their income goal?

As you build your net worth, you get more granular control of the percentage of it that you can put into any one investment. 

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.