No, that's not how it works. The rocks release a constant field of electricity automatically, it's not something you control, it just happens.
If you raise four of them in a square formation then the electricity will pass between each other until the rocks are destroyed.
If you just raise one, than the electricity will encircle the object.
This technique is basically just a Greater Earth Style, except that you use lightning chakra to form the shapes and the shapes have the added bonus of being able to float + electrocute people.
Yes, you can have the rocks rise from pretty much anywhere and they can be as small/gigantic as you want them to be.