You your self said the front wheels can lift off the ground, and you can almost see it in your picture. Your steering control, and the majority of your cars breaking comes from those two front tyres. If they aren't heavily weighted on the ground, your not gonna steer or brake under an emergency stop or even at high speed cornering.
Regardless of the trailer brakes; If you think about it, when those trailer brakes are applied heavily, the inertia of the load which has a high center of gravity is going to try and overtake the axles. This means it will try and lean forward, and as a result push the rear of the car down and raise the weight off the front even more.
Do you know any decent real engineers? Ask them and watch them raise a brow, as it's quite a bizarre idea you have there.
Did you know the majority of Truck and Dog Trailer combined vehicles that have accidents are due to the dog trailer (rear) being overloaded? Like I said before, thats due to how the heavy load at the rear 'pushing' makes the vehicle dynamics all wrong. And they have bigger rear trailer brakes than any goose neck trailer you'll ever see.
I'm not trying to be negative, i'm offering constructive critisism. I'm the first to agree though, there's nothing wrong with trying to think "outside the circle."
