There are several ways now to burn natural gas without releasing even a single ounce of CO2 into the atmosphere. For example, one way cracks natural gas into hydrogen and into solid black carbon which is a fine powder, and easy to store away.

Natural gas will be an integral of the energy mix for the next 50 years at least.

Eventually, yes. One nice thing about the US natural gas boom is that power plants for natural gas have much lower capital costs than coal plants, so there will be less screaming when they are eventually shut down.

Eventually, but for now it's a 50% reduction over coal.