Why can't I ever get momentum transfer just right?

Fixing the other two issues with Y axis momentum transfer opened a new issue with X axis momentum transfer.
Now, when objects collide, momentum is transferred IN THE WRONG DIRECTION. Frictional forces are applied in the correct direction, but not momentum transfer.

Magnitude of the energy transfer is still OK, but it is applied in the wrong direction to the object with lower momentum.

High-Velocity Impacts on the Y axis cause infinite energy exchange. Objects stick to one another and oscillate rapidly. Maybe it has to do with the force of gravity interfering with or adding to the energy transfer?

When one Kinematic Body is on top of another, the acceleration of gravity is shared as "Momentum", making the two bodies oscillate really quickly. The displacement of the oscillation is very very small, and while it varies based on the masses of the two bodies it is never more than a few pixels.