Magic in the Inheritance Cycle

So i am actually surprised that Inheritance hasn't been brought up anywhere in the forums that I can see. And I wanted to ask what you guys thought of the way magic was portrayed in these books. I like the idea because it makes magic an important but dangerous thing, and also puts a different twist on magic unlike i have ever seen. The idea that each time you use a spell you use up the amount of energy it would take to "physically" do that act. Yet, in turn, spellcasters are able to handle more than an average person. It seems to me that this "essence" that has been introduced, and how you only have a limited amount to imbue into other heroes, and the land, etc. seems to be slightly reminiscent of that idea.

I also like that it limits magic to a certain degree, without saying, "oh theres just a 'magical law' that says you can't do that". Inheritance describes it saying that its impossible to do something like raise the dead because you could not bring a persons soul back and you would expel too much energy from yourself in trying to do so, thus killing yourself in the process.

Another example showing all the different ways magic can be used can be seen towards the beginning of the third novel, Brisingr, when Eragon states that:

"...There are almost an infinite number of ways to do something with magic. For example, if I want to light a fire, I could light it with heat gathered from the air or the ground; I could create a flame of pure energy; I could summon a bolt of lightning; I could concentrate a raft of sunbeams into a single point..."

And in turn, all of these spells can be counteracted by enemy magicians, but at the cost of the energy used to put the elements back where they were. I personally would like to see battles where you have your troops fighting and you are basically just trying to counteract the enemy channelers spells while trying to get your own spells off before one side of troops wins the battle below.

Also, as I stated above in imbuing essences into the world around you to make it "habitable" again as already stated. In turn the opposite could be used as a strategy element. If you find yourself weakened by a previous battle you could suck out the essence of the land around you to replenish yourself (much like Eragon does in Brisinr) at the cost of your people getting mad possibly because of your nations civics or whatever. Or as another example for evil civs would be to take the life essences of your own troops and use it to create and unleash a massive spell.

And like I said before, I like the uniqueness of this idea behind magic and magical usage (especially in battle strategy! for an example refer to the end of Eldest) I hope I did not give out too much plot information of Inheritance for those who were planning on reading the series because I dont like it when people do that to me either  And I'm looking forward to what you all have to say about your opinions of the way magic is used in these novels, and its possible implementation (or something similar) into Elemental.