Would a shareholder certificate as  opposed to a deed/title be sufficient in the event of such a tragedy?  

Her email is sufficient evidence of written termination.

Your basic insurance policy with $300,000 in liability coverage should be sufficient in 99.999% of all lawsuits.5.

For the cash out portion, you need to qualify for the loan and your collateral, i.e. your property, has to appraise sufficiently high enough as well. 

My suggestion is to get really good at estimating ARV, or the price the property will sell after it is all fixed up, and allow there to be sufficient returns for the end investor AFTER you also take your wholesale fee out. 

Think about it:  at the end of thirty years you will have a property free and clear and it didn't cost you anything to pay back the loan (yes, assuming you keep it rented sufficiently, your maintenance costs aren't too high, etc..).  

Your basic insurance policy with $300,000 in liability coverage should be sufficient in 99.999% of all lawsuits.5.

It boils down to you having sufficient knowledge of construction costs and practices to ensure that  your projects are properly priced and executed.

Meaning if Wholesaling is bringing in 10k a year, and you can't save any of it--maybe get a W2 job (and a 2nd W2 job) and sleep on a relatives couch for portion of the utilities and a portion of their rent.If wholesaling is bring in $10k a year vs. for instance Minimum wage in California is $15 hour which is about 4 months work full time to make $10k --consider where you can make the most money.Good Luck!

Sufficient insurance, cash funds, financial reporting, etc.