Taking care of elder dependents can be exhausting and time consuming - don't underestimate it.Can you find fewer properties that will cashflow the same or better, or were you hoping to have that 10-12 to spread the risk?

Las Vegas has very limited land resources which are quickly being exhausted.

They all say I can withstand the negative cash flow each month.  

In another unit it’s working out great, but I’m looking for something to withstand a bad tenant.Clearly 4mm is too thin, so where’s the sweet spot???

The second one, there are 2 gas boilers and 3 water heaters running their exhaust through it.

Bottom line:  Your margins should be able to withstand a $10K error that would cover mechanicals.  

I am new to Real Estate Investing and am so exhausted from all the seminars and books, and programs and have never been more confused.

Essentially, you are paying for something you hope you never have to use....but if it does happen, you have multiple parties in your corner fighting off a claim, for many years if needs be, and even if the limits of one were exhausted, you have another...and the legal fees alone could be large, so nice to have the insurers footing that bill and having an interested in settling or disposing of the suit....great question, though, could you be overinsured?

For example, the bathroom didn't have an exhaust fan.  

My current mortgages on my primary and investment properties already exhausted all of my usable income based on DTI calculation.