Our shower diverter leaves more water coming from the faucet than the shower head even when turned completely to the shower head direction. It also happens to be hot water which is really wasteful. Any help?

Sorry, but you need a new fixture unless you can figure out how to take it apart.

Your mixing valve not only controls the balance of hot vs cold but also where it comes out, shower head or spout. In your case the directional part of the valve is not sealing and needs to be replaced or rebuilt. What brand, hope its Moen.