"I look at the rear wheel as being a flywheel that stores energy that really helps to conserve momentum and make a fixed gear a better climber than an equivalently geared ss."

The momentum-conserving properties of a flywheel are dependent on the mass and distribution of mass of the flywheel, and wouldn't vary significantly due to fixity or not. If you want more momentum, you need heavier wheels, which are not noted for increased climbing ability.