1
The nucleus is not in a gravitational orbit for electrons.
2
The general position of electrons is to bounce off one another within a certain range. This is the current model of various subshells. (The distances shown below are exaggerated to make the effect. The Range is 1000 times larger than you would think from the textbook graphic.
Yes, electrons do move, but they are more in tiny pendulums that position and move using q(E+ vB as the opposing forces.
3
But, I believe there is an additional energy level that is not yet fully understood. It is called rotational energy, and it is either angular momentum or spin. These are the most mysterious aspects of quantum physics, as they only exist in unit jumps.
My life’s work is to find out why they do what they do. Rotation is the better solution. However, it will take years to find the right combination of 3D engineering and complex 3D engineering.