An episode a day

[Rares]

There's a lot here which I think you're right about, but not everything. I personally enjoy this episode, and agree that BBBFF is a great song. The introduction of Cadance was a seminal moment in the show, and one not handled all that well, imho. Leaving apart the destruction of lore, it makes absolutely no sense Twilight wouldn't have known who she was. In the comics, her brother was head-over-hooves for an Alicorn named Cadance, there were only 3 Alicorns. The invitation even said "Princess," and her name isn't that different.

Which brings me to my chief disagreement with what you said: everyone but Twilight acts like idiots. If anything, I think Twilight was the biggest idiot in this episode (sorry Love, I know it's not really you), with the possible exception of Princess Celestia. Not only for the aforementioned reason, but when she discovered something was up, rather than let Celybeans know right away, she makes a huge scene giving Chryssy just the ammunition she needed to pull off a successful deflection. The others had no prior experience with Cadance, and can be easily forgiven for failing to realize something was wrong, (except Cely) however, Twilight's foolishness can not.

Not only that, but with the sheer number of changelings which attacked, the M6 still managed to defeat a great many of them in (mostly) melee. The changeling's military nearly had it's butt handed to it despite the enormous advantages of numbers, surprise, and leadership decapitation. Considering this, and the way they have shown themselves to be an active, malicious threat, I have to wonder why Celestia tolerates their existence. She should wipe them out completely, yet she doesn't, and doesn't even seem to have any reliable way to detect them permanently in place. The Princess Celestia in Twi's Equestria would never behave so recklessly with the safety of her ponies, neither would Twilers herself. Fortunately there are no changelings in her world.

So, anyway, I think, rather than what you said, it was only(mostly) Twilight that acted like an idiot. Despite all these problems, though, I really do like these episodes. Hopefully you'll enjoy part 2 more than this one.

There's a lot more with Part 2 that I dislike more than the first part. Obviously I'll get into that a bit more later, but I actually really dislike the melee fight, I feel like that didn't fit, and I dislike the number of similar action scenes that follow in the show.

In the case with Twilight in the episode, it definitely seems like a matter of perspective. I think you're right in that case that Twilight should have handled it differently, and then there is the case of the Mane 5 not having any experience with Cadence before (and I'm certain Rari has put up with at least a handful of Bridezillas before) it's that instance of dramatic irony that kind of nags at me. We as the viewer know Twi is right, seeing everyone else act the way they do just makes them seem like going along with the villain's scheme. Which again, not so bad here, but considering how it continues later on in later premiers and finales, it's really tiring.

There's a lot more in the next episode I'll bring up, but while I don't think this was bad in itself, I think it definitely opened up the doors for a lot of things I don't quite like in the show now.