"Do you know how to carve, do you know how to read?
Do you know how to color, do you know how to question?
Do you know how to ask, do you know how to sacrifice?
Do you know how to dispatch, do you know how to slaughter?"
-Odin (Havamal, S. 144)
In runework, many aspects are fairly flexible,especially when you when you get into bindrune work and galdrastafir. However, the runes are not witchcraft. They are a norse/germanic/anglo-saxon practice that rely heavily, if not entirely, on the cultural and spiritual customs of those peoples. Therefore several aspects of their creation simply cannot be ignored.
The runes were discovered by Odin, after hanging for nine days and nights on Yggdrasil, impaled by his spear. This is why understanding the spirituality around it is so important - they werent created by men, don't belong to men, and should not be changed by men.
Next, the life-giving ritual, where we give it life through shape, blood and breath. it's a nod to the way Odin and his brothers gave life to the trees. Through this new life, they connect to the wyrd (too complex to summarize properly. But essentially the force of fate) and, for divinatory purposes, reveals it, or in the case of binds and staves, manipulates it. They don't get "charged." they are given life of their own and their power comes from said life. Not your "energy." and though charging is a valid practice, it is not a valid method for the runes. Though, if you wish, you may certainly charge them before, after or during the life-giving.
The "do it however you want" approach is, at best, foolish and insulting and should not be taught to beginners. The understanding of the runes takes years of work, and i can guarantee you, that you will never know all or close to all there is. To call yourself a runeworker is a very serious thing that requires more than just one or even several books and a rune set.