Wil...
The only way you would reduce the load on the engine by using an electric water pump driven by the alternator would be if the pump itself consumed significantly less power than the stock pump. So the electrically driven pump would either have to be quite a bit more efficient than the stock pump or smaller in capacity than the stock pump.
Driving a water pump electrically adds two additional layers of inefficiency: the alternator is not 100% efficient, meaning it will consume more power than it generates to run the pump. And the electric motor that drives the pump is not 100% efficient, meaning the less-than-100% efficient alternator has to work even harder just to make enough power to drive the pump.
Drag racers frequently use electric motors to drive stock style water pumps. They do this because they do not run alternators (they charge the battery(ies) between rounds) so they are indeed freeing up a bit of engine power. I suspect this is where the misperception that an electric water pump reduces engine load comes from.
Think about it this way-- what would happen if you used an electric motor to drive the stock water pump on a street or road race X1/9? You'd have to have an alternator, right? So where would the reduction in load come from? If there truly was a reduction in engine load then you would have just discovered perpetual motion. In which case, you should just drive a big electric motor with a big alternator running off the electric motor, and build an electric car that never needs fuel. Sadly, that isn't possible. Incidentally, the many inefficiencies in the power generation, delivery, and charging system are never mentioned by the electric car crowd, but that's getting off-topic.
Bottom line-- as stated above, the only way to reduce engine load with an alternator driven electric water pump is to use a pump that consumes enough less power to offset the inefficiencies in the drive system. Even if that's possible, the gains are likely to be minuscule. And unless the overall system weighs the same or less than the stock system you will lose performance (handling/braking/acceleration) due to the added weight. There is no free lunch here.
Frankly, the X cooling system works just great when it's in good shape. IMO, fitting an electric water pump would be an enormous waste of time. There are far better ways to gain performance on an X.
///Mike