Appreciate the responses!
I removed all wording about Proficiency returning it to cavalier default.
On the Dragon Dive:
First of all, yeah, the language could always be tightened up!
It should be noted that I took the baseline for how effective this archetype should be from a cavalier that had the feats Ride-by Attack, Wheeling Charge, and Spirited Charge. Because all cavaliers that charge have those feats (they do!). Since the Dragon Knight is unmounted, I had to bake those in somewhere so it could stay competitive. Hence the wording in the 3rd and 6th levels of Dragon Dive, and the 2nd level order ability are variants of those feats. You can do similar with spring attack wording, but I figured I'd keep it as standardized as I could.
The Dragon Dive / Dragon Jump / Jump Attack is the bread and butter of a Final Fantasy Dragoon, so my philosophy was to make their signature move accessible. AND I desperately want to avoid the schlock that is Branch Pounce. So I'm reticent to place mechanics that require high ground or set DC's. If I require high ground, I'm denying access to the signature move...which is most of the time in practice. There are a lot of low ceilings in the game. If I require an acrobatics DC, it is relatively easy to find a way to blow it out of the water and then you either gain a scaling bonus above the DC or, if it's set, why make it at all if it's automatic success? Ultimately I removed that wording from Dragon Dive entirely and simply declared that it's "acrobatic yadda yadda" opening up the idea of the Dragon Knight leaping horizontally, or off ceilings.
As you point out, the original Cavalier's Charge does grant a bonus of +4 when charging which got left out of my document, so I can add it back in.
Finally, thanks specifically to Cyrad for that effort! The idea of Impaling Critical is interesting. I admit I'm not sure how valuable the current 18th level ability is, so I'll keep that as a possibility.
Keep it coming guys, critiques and counterarguments!