Name someone who can ask what Big G is doing and get an answer. I'll wait.
We dont know.
The Dresden Files is written from the PoV of Dresden, who is still a baby in the setting's power plays and spends almost all his time in one city in one country of an entire planet.
Also worth remembering that we dont actually know that the Crown would work on big White G.
We're not even sure that it would work on a loyal angel; it would do something that Uriel would prefer not to happen, but that doesnt mean that it would be able to See.
Its not an unlimited power, as we can tell by how it goes null every time we point it at a decision that hasnt been made.
We are, however, the only fish in the pool with nuclear codes in our pocket. Knowledge is power, and when you can get any knowledge... even what can make Angels Fall...
A LOT of people would say screw everything and devote everything to killing Molly if they realized just how powerful her Crown is. That Odin is poking around is a direct threat to Molly and everything around her, and if he actually understood what secret she was hiding he wouldn't want to know. Ironic, considering his own lust for knowledge.
1) That is not true.
Ivy has the actual, literal nuclear codes in her head, as well as secrets of every faction that uses mortals in the setting. Everybody knows that she has those secrets and more in her head because how her power works is more or less public.
And she's not the only one, like when Nicodemus TOLD Harry about his brother before Harry even knew he had one.
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2)Yes? A lot of people are also fucking stupid, what else is new?
That kind of information-gathering capability is valuable, and a lot of people and factions would devote effort to trying to get it under their control, or denying it to enemies.
Molly is young enough, mortal enough and new enough that the Taylor Hebert codicil would still kick in for most people who would take a look at a teenager and go "I can take them". Until she shanked them.
Thats the reality of many new Powers without an established Power explicitly backing them. People test them for vulnerability.
One of the benefits of the Fae favors that Molly is known to wield, and the company she is known to keep, is how they act as a passive filter to most opportunists, who might not believe in Molly's personal and organizational power, but believe very much in the power of Summer and Winter. And in Amoracchius the Dragonslayer.
Which deters most of the opportunistic riff-raff.
PS
We cannot make angels Fall. I dont know where you got that idea.