For me retaining the extra equity made more sense and provides a better return.

In short, my sibling is the bank, and I am everything else (the sweat).This works out well, because I am still saddled with student loans at present and do not have capital to invest, whereas my sibling has capital to invest and needs to diversify their retirement portfolio’s income streams.Income Before Taxes will not be disbursed, but retained to buy future properties.

I retained their first month's rent, the security deposit and returned their pet deposit.  

I don't mean that in a negative way... you would retain a higher proportion of the equity.

Landlord retains the right to determine how and when the repair will be done, in accordance with federal, state, and local law and codes.

I agree with @Seth Williams   Retain a lawyer to review the case, send a demand letter, and potentially defend yourself from a lien. 

Offer to pay a retainer up front for the time you are taking to find your incredibly niche product and you'll have better results.

This will retain a power of foreclosure for you wil gaining control of both the property and the loan.  

Similar to that of financial planners or real estate agents who are all paid by a percentage, they maximize their profit by doing as little as possible not the other way around.For instance, say I am your PM and you retain me by 10% of the monthly rent of $1,000.

The retaining walls are temporary and will need to be solidified or replaced.