What is your point about Amb. Gration? That he had at least five other bone-headed practices, so violating the Federal Records Act is not really an offense worth caring about? Even if true, does this help an official who presented Russia with an "overcharge" button for diplomacy, who wanted to obscure the events leading up to Benghazi because she pretended to not see what difference it would make to understand the truth, and who flagrantly violated State Department policy while her immediate underling was persecuting an ambassador for violating that same policy?
Your point is that it must have been against the rules because Gration got fired for doing it. But he was not fired for setting up a private email server, he was fired for a whole host of offenses that included installing his own special non-departmewnt-approved internet connection and using the email address from the ISP for his official duties. If you actually paid attention to the firing at the time you'd know their major problem with that was not that it was not a state.gov address, but that it's really bad optics when your Ambassador insists on installing an internet connection in his bathroom. State exists to be good optics.
As for the rest, you're really stretching. The Russians didn't seem to mind that button was spelled wrong (altho they did take glee in pointing it out), and the "Reset" worked fine until the Maiden protesters forced things. She's taken responsibility for Benghazi, which is pretty much all you would ever expect apolitical appointee to do.
Perhaps Colin Powell also violated the Federal Records Act.
If Hillary did Powell did. So did President Bush and Rove. She will never be attacked for it any place that matters because the people who can do that would also have to nail their own party.
State Department policy did not officially require use of government email servers (except in emergency situations) until the year he left the office.
State department policy did not require the Secretary to use a state.gov address until Kerry took office.
If he wants to run for president, there should certainly be a public debate over what he did or didn't do with regards to that. However, his primary defense -- that most of his emails were sent to government addresses -- is also Hillary Clinton's primary defense.
I did not directly address your facile arguments about what a foreign government would want from a Cabinet secretary's email because I thought the holes were so obvious: Hacking her server would give far more information than they could capture from a single conversation in her house, it is easier to do deniably, and at any rate the undeniable breach of federal law is in failing to put federal records in proper custody for preservation and oversight. For high-level officials, mishandling classified and SBU information is a real risk (and what the IGs here want to be investigated), but is not such a clear violation.
Below the Secretary of State level that's the only concern, because they don't know anything that hasn't been put in paperwork.
At the Secretary's level that's not as big a concern as the shit that isn't in the paperwork.
The things China cares most about are things that would not be put in an email to anyone. Very few Presidents are gonna put on official paper that a mission to stabilize some conflict involving China is a bluff. Very few would put on paper that they'd nuke Shanghai if the Chinese back down. A Secretary of State's impression that Obama is very very concerned about the South China Sea, and would actually increase his paper-commitment to it before backing down, or that he's only there because of everyone else and would back down rather then lose people (even if that's not what the paperwork says) is several thousand times more valuable then all the paperwork in the Federal government put together.