Opportunity at hand, scared to take the leap

[Kanwar Sodhi]

Hello guys, I've been on BiggerPockets for a long time learning and reading. I was a given an opportunity to purchase a place for $75,000 which would yield a monthly cashflow of $363 if I amortized over 15 years or $515 if I did 30 years both with 20% down and $2,000 in closing costs and estimated loan interest amount of 5.00%. This cashflow is after using the biggerpockets calculator and reserved 5% for vacancy, 10% for CapEx, 10% for Repairs, 10% property management fees.

The person selling it is a constructionist who buys distressed properties, fixes them up and sells them.
He's selling it as a turnkey, obviously, and also says he'll act as the property manager (taking 10%) and take care of putting tenants into place and stuff like that. 

Cash on Cash ROI is 25%

My fear is that I don't have a great job to support things like the roof going bad or the boiler going bad. These big costs will destroy me if they occur and I don't have funds to get these fixed right now. 
What would you do to insure that you're safe for the next at least 5 or 10 years from stuff going bad.

I know being a landlord is lucrative, people do it and people are making and getting equity, but how do I get over these fears so when I pull the trigger, the risk is less.

Thank you for your help in advance.