The Charm doesn't do any more than stated- the only Attribute or Ability that *it* increases is Intelligence. The Charm also defines an expectation regarding familiar Essence, Willpower, and Virtues, because these are more relevant for spirits than for most animals.
Now, Familiar *is* a kind of lame Background, so the Storyteller is welcome to pump familiars in *general*, but the Charm doesn't give them more than it says. :)
Assuming that god-familiars have to have Bureaucracy is assuming that the Celestial Bureaucracy functions more like infinite harmonious heavenly clockwork than a real bureaucracy, and I'm not sure that's a good model. If they all had Bureaucracy, then I suspect the world would be in a much better state- while it's a problem that so many gods and Sidereals viciously manipulate Yu-Shan, it's a bigger problem that you have powerful, cunning, vicious gods whose idea of bureaucracy *is* eating the honorable opposition and their little memos too. I tend to assume that most god-familiars- with the exceptions of god-rabbits and other easily stressed god-animals- just do their job with an animalistic lack of introspection, not worrying too much about the fact that their reports are neither incisive nor politically useful.
That said, I'm not adverse to having god-familiars develop skills over time- although I tried to buff Sidereal familiars to the "useful" level anyway, so if you're going to add more than "picking up a dot or two of new Abilities over the first few years as a god", you might consider cutting back on the number that Sidereal Exalted can have.
I figure, to be honest, that the most useful thing to do with a Spirit-Shape Companion is to have it wander around dematerialized. Cat-familiars who poke around the enemy commander's tent without manifesting, horse-familiars who appear out of "nowhere" when needed, and so forth. Yes, this isn't a unique super-ability, but it seems worth the Charm slots to me. :)