If there is "waste" energy, does the Law of Conservation of Energy still apply?

Explanation:

Yes, the law of conservation of energy still applies even if there is waste energy.

The waste energy are the transformation products of energy from one form to another.

According to the law of conservation of energy "energy is neither created nor destroyed by transformed from one form to another in a system".

But of then times, energy is lost as heat or sound within a system.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.