I don't think it is JUST "a plain and simple description of a god's nature" although I do think that is by far the most important part. If you accept this and follow it rigorously you'll never be taken in my supernatural religion, and that in itself justifies its position as doctrine one.
But I agree that it states something that we feel through anticipations -- i think it is fair to say that most humans feel naturally that strength in the ability to sustain one's own happiness is something that comes through self-sufficiency (which is not the same at all as asceticism) and that if we are dependent on sustenance from others for our necessities then we are by virtue of that "weak" and easily knocked off balance.
Personally I emphasize that point and would not be overly concerned about "being on the receiving end of their anger." Yes that is a practical part of our situation as humans, but I would not think that that consideration natural extends upward all the way that you may be taking it. I think even Epicurus' conception of godhood means that at some point the "strength' side washes away much concern about being on the receiving end of anything negative. I would think that as a god if you haven't arranged your affairs strongly enough that you are no longer concerned about the wrath of other beings, then you aren't yet at godhood. Yes a god wouldn't do naturally be doing anything to create trouble for itself, but just like in this world where we aren't surrounded by people whose wrath is not always rational, I would anticipate that a true good wouldn't be concerned about being on the receiving end of "irrational" anger either. (I hope that makes sense - the point I am suggesting is that I think an Epicurean god's status of being able to overcome all forces of destruction to itself would imply strength against ALL forces, no matter whether the gods action did something to provoke anger or not).