Don't accept ANY partial payments.

I have an accepted offer on a luxury cabin in the sierras.  

Not getting an offer accepted is part of the journey.Great list!

Many banks handling tax escrow accounts for mortgages have mistakenly thought there was one tax due twice/year or totally missed one of the taxes.Investors should research the SEV and the Non-Homestead property tax millage rates to project what the property taxes will be after adjustment.

Unless the medical condition meets the state criteria for early termination and that the medical notice does not appear to suggest that, you cannot terminate the lease outright/immediately but that you will begin to market the property for rental and upon securing an acceptable tenant, the lease can be terminated pending a satisfactory property walkthrough indicating no damages. 

I've seen a lot of your posts and I'd be interested to know what you think differentiates those 'few' investors that do manage to scale their businesses from the 'most investors' that are unable to achieve a gross ROI that would generate acceptable profits for a sponsor and investors?

He is securing expensive debt, not debt through a bank, isn't putting any capital into the deal and structuring the equity investment in a highly risky manner without any upside offered to the investor.

., pool)-LandscapingNot Acceptable Renovations:-Commercial Use (e.g., turning a residential property into a commercial property)-Temporary Structures-Non-Residential Buildings (e.g., barns, stables)FHA 203(k)Minimum Down Payment: 3.5%Minimum Credit Score: 620Minimum Loan Amount: $50,000Maximum Loan Amount: $524,225Occupancy Types: Primary Residence ONLYUnit Maximum: 4 UnitsAcceptable Renovations:-Structural Improvements/Reconstruction (e.g., adding rooms, bathrooms)-Cosmetic Enhancements-Eliminate Health and Safety Hazards-Energy Efficiency Improvements-Major Landscaping (e.g., grading, tree removal, adding walkways)Non-Acceptable Renovations:-Luxury Items-Commercial Use-Temporary Structures-Non-Residential BuildingsBoth of these renovation loans are similar in many ways, but the key differences are:1.

How much is an acceptable fee for doing this? 

Quote from @Gary Campanaro: I wouldn't consider it unless it were agreed to up front.Cancellations are part of her business, and she needs to accept that.