If so do you intend on self-managing it or hiring a property manager?

Always hire a contractor or get expert opinion on something you do not fully understand.

I have also hired her as my bookkeeper. 

We certainly could not have done it with our GP team - it takes a village :) Yes, we hired a coach - our success came with our 2nd coach because the first one was a bust. 

I will have to hire the work out.

I am thinking we as landlords can do the following but I am not even sure if that is enough to get landlords off the hook if a gas explosion does happen:- hire a licensed plumber to inspect for gas leak and gas pressure on an annual basis-install a gas leak detector or alarm in the rental unit-spell out in lease agreement that tenant is prohibited from removing the gas leak detector and tenant must notify landlord immediately if at any point the detector stops working-do semi annual walk through inspection of the rental unit to make sure the gas leak alarm stays installed and is working properly and that the gas stove is working properly.Is there anything else we as landlords can do to minimize our exposure to being sued in the event of a gas explosion in the rental unit ?????  

Hire electrician to move any electrical from walls we’re removing 4.

You might consider hiring an attorney.

Did some research, but of course, I'd hire contractors for those jobs anyway.

I wouldn’t have the seller fix it because you don’t know they could hire the cheapest guy to do the job just for the house to close.