Adding HW to Boiler

Hello. I just had my oil guy here servicing my boiler. I asked him what his thoughts were on switching to gas and he of course told me it wouldn't be worth it for me because in my area the prices will go up within the next couple of years...I don;'t think it would be smart move for me because I don't plan on staying here more than 5 years.

I then asked him if an electric hot water heater would help with the cost. He said it would but I would have to be careful because it will damage the boiler if the boiler isn't running. He explained to me what to do. If someone could just read this to make sure I am on the right path...

-Put a valve on the water line right before it goes into the boiler (the IN outlet). He said this way I can run it once and a while.
-Turn the temperature setting the hi and low all the way down so it still runs (which I am confused, if the water running in is turned to off will it still be getting water to maintain the settings or does it run off the water line going in for the heat?)
-Put two valves on top of the hot water heater.
-Then just T in the lines.