When I see figures like that, I suspect that the Report has been rigged by someone using pre-determined desired outcomes, rather than cold hard correct analysis. 

Searching for confirmation of pre-determined biases. 

I would say my biggest advice is use this time as a pre-determined study  / saving along with screening potential markets you might move to.

If you are trying to get a HELOC on a house you recently took a loan out on, then the bank may require you to service the loan for a predetermined amount of time before considering a refi or line of credit.

TLDR: What agreement should I write between my grandmother and I so I can take over her house (mortgage payment, agree to buy the house at a predetermined cost), while we keep in her name and then finance/buy it at a later time?

Often times we get emotionally over-optimistic about a particular property and we lose sight of the potential downside.I'm not sure if youve ever heard of a Monte Carlo simulation, but what that does is take your projected numbers and runs them through a predetermined number of simulations, sometimes over 1 million different scenarios if you wanted it to.

.- Our lease includes a "Purchase Option" clause, which when the tenant signs states that if they meet the conditions of our 4 year program they can purchase the property at the pre-determined price.

This would have to meet predetermined criteria that you set though, because you don't want them to send you everything under the sun that is a crap deal. 

Would it be a strategy to offer to cover the default amount or someway get in to contract on basis of saving the home from foreclosure and maybe think about renting to them....or allow them to continue to live there until a pre-determined time and then get viable tenants in???

The % is pre-determined and the only way you affect that as the buyer is whether it all goes to the seller’s agent and their brokerage or if it gets split between 2 agents and their brokerages.