Manual Heater Hose Valve

I don't get it. You plan to remove the factory water valve that you can operate with the selector panel inside the car and install something you have to go out under the hood and turn off and on?

I don't see where you are "eliminating" anything. You remove one object and replace it with another object. You still have to have heater hoses to conduct the coolant from the block to the heater core.

I admire your effort but perhaps you should consider something else to modify besides this idea.