The problem with what is valid and what is not. What is perfect and what is not depend upon one thing to me, and people are going to disagree here, and that's their prerogative. Shepard is a soldier (whatever) and Shepard's orders, regardless of your journal entry, from "the man" are contained in this sentence: "You're wrong, Shepard. Dead reapers is how we win this." Complete your mission.
But how you've gathered everything that "targets every single reaper in the galaxy" and put that onto the crucible, why doesn't the crucible just target every reaper in the galaxy with it's death ray? You'd think with that level of sophistication of space magic it should be able to do that, right? But if it did only that and nothing else, who would pick control or synthesis? But they threw on "destruction of all synthetics" and "destruction of technology" just to sour it enough to make you consider the other endings.