Nope. Saber doesn't have insert songs, so far. There was a lack of it with Zero-One, too. Well, for the other riders, I mean. Zero-One himself had three to his name.

Of which only two actually appeared in the show, if I'm remembering right

I don't know why but Touma's twitchy reaction upon seeing Tassel cracked me up.

I think the "I'm the one who decides how this story ends" will be a major factor in convincing Kento to join their side, as he'll change fate by making his own ending, not the path laid out for Kento.
Legiel getting his memories back just when he dies, like people said, could be expanded upon, later having to deal with it and what to do. But I feel they wanted to add more of a tragic angle with him by acting as the sacrificial lamb and acts as a stepping stone later for Zooous and Storius to be expanded upon.

Did anyone else notice how Touma said Kamijo's catchphrase when he transformed into Dragonic Knight?

Oh, yeah, definitely! It's a neat detail since both said it during moments where they're about to save a child.

Sometimes I feel like that should've been his catchphrase.

Okay, first and foremost: Saber's theme song does not work as an insert song for dramatic fight scenes. It's way too upbeat, happy and, most importantly, terrible.

Second: Tassel with a real mustache somehow looks even more ridiculous than Tassel with his fake mustache.

Those two points aside, holy crap, this was an amazing episode. Touma's repeated transformations to confront the boy was intense enough, but if you had told me, just two months ago, that I would get misty-eyed over a scene in Saber because it was so emotionally powerful, I would never have believed it. Everything about that, though, was so good. The lost lonely dragon, Touma helping him feel his friends, the new dragon coming to join him... man, that shit was fantastic. Legiel going berserk felt a little random, but it led to some good moments with the supporting Riders and a really nice final showdown with Touma.

Man, I actually got excited when Tassel showed up. That's how good this episode was.

Idk, Almighty fits the bill as some sort of triumphant theme, so it kinda worked for me in this fight. Put a smile on my face, too. Tho, I do, however, would've wished it was the ED song instead.

Did Tassel's mustache change? It seemed the same to me.

I don't think the ED song would fit the battle at all. Would've ruined the dramatic mood with its super cheerful tune. At least ALMIGHTY has a terrific triumphant trumpet tone.

Oh yes, that moment was fantastic! I really do like how he calls back to his "hero" in a fitting moment. Though, Touma's actual catchphrase is still very appropriate.