Applejack would admire the work ethic of the average imperial citizen but would be untrusting of the royal family if she learned of the dishonest means we sometimes employ to protect our people.
and then we remind her of all the secrets CELESTIA kept.
like the SMILE secret service (BonBon/Sweetie Drops was a secret agent), how she basically allowed Luna to be forgotten (and arguably most villains too, though that might not be her fault), how THE WHOLE SENDING TWILIGHT TO PONYVILLE was based on a "white lie" of Nightmare Moon not being real...
The only one that would have a strong dislike of the empire as a whole would be Fluttershy who would be horrified by our desire to completely dominate nature and change it to better suit us instead of finding some way to live in harmony with it.
Funny enough Fluttershy basically tamed all of her animals. This goes back to how, to a gryphon, what the Equestrians do is basically "enslave/heavily regulate nature" in a way even WE just never managed to (...
yet...).
Good point, I guess she'd be ok with us then. Now that I think about it Twilight probably would too once she recovered from the initial culture shock and looked into our history.
I think even Applejack would come around once you show the hypocrisy of holding us to higher standards that she does her princesses (as they DEFINITELY keep multiple secrets and have AT LEAST one secret organization).
She'd be stubborn, and initially deny it... I think Celestia would later on admit that, sometimes, heads of state just HAVE to lie and do distasteful things in order to minimize casualties and suffering. We could easily point out to how we basically "freed/kidnapped" the slaves in a series of deniable ops, for example. or even to how we're trying to deal with the changelings in a way that will NOT Result in calls for genocide.
Fluttershy... I don't know. She's the strangest mix of "soft" and "hardcore". I don't think she's actually as naive as she sometimes seems, so I'd like to think she'd undestand the necessity of many of the things we do, even if she wouldn't like them.