I replaced my anode rod recently and flushed the tank. The water was very clear and the anode rod was mostly in tact.
I think it is a waste of money to replace a water tank if it is in good shape.
Highly recommend getting a steel drain pan. Can get one on Amazon for $40.
You will need an impact wrench and a very stable platform to stand on to replace the drain pan. I did it myself but you will need help unless you are in good shape.
Amazon.com
Amazon.com