1. I don't understand what you mean by "aspect".
2. A single charge has zero potential electric energy
since there is nothing that will put a force
involves the ability to do work
where work is defined as the ability to prove a force
over a distance
. I am using the underlines to denote that these are physics terms with very strict mathematical definitions (not to be confused with non-scientific versions of these terms).
If you take an Electricity and Magnetism course, you will do a lot of mathematical problems involving all types of energy
. The law of conservation of energy
always applies, you get out the amount of energy
equal to do the amount of work
you do to the system.