Arcane Archer Lore: A great non combat feature. You even get options to choosr from, which is A+ in my book.
Arcane Shot: The design of this feature is totally different than other fighter subclasses. I don't want homogeneous designs but I'll take it over worse designs. Not scaling in number of uses or power until levels 15 and 18 respectively is a design choice I disagree with. Especially, when the number of uses per short rest is capped at two. The shots themselves are fine even if they aren't what I would have done.
Magic Arrow: Fine as an accompanying feature at this level. Certainly in line with the magical nature of the subclass. I don't love that it's arrows only but that's a small gripe. WotC is clearly afraid of making sling stones and bolts too cool.
Curving Shot: Honestly, this is the real defining feature of the subclass for me. The mechanics and flavor are great. As you said it partners very well with SS.
Ever Ready Shot: Other classes have similar features to this one like the monk, sorcerer, and battle master. It is a mechanic that I hate with a passion because it takes too long to come online. This should be a level 7 feature at the latest. Or do what the Psi Warrior did and let the archer recover a use of arcane shot once per short rest.
Overall:
- It doesn't let you do the cool thing you want to do enough.
- It fails to do anything new after level 7.
- The fighter chassis already has this issue after level 9 and the subclass shouldn't copy that mistake.
- You get two rounds of combat per short rest where you aren't just a slightly more accurate fighter with a bow.
- I think a better execution of the arcane archer idea can be done with other classes like warlocks, rangers, and bards.
While I have different concerns with PDK and Champion these are my reasons why I think AA belongs with them on the lowest tier of fighter subclasses. The Cavalier may not be the most powerful fighter subclass but I do think the design execution is better, the features are more varied, it has a good balance of resource limited and unlimited use features, and it barely uses it's bonus action so it's a great target for PAM, GWM, Shield Master, dual wielding, or any other bonus action heavy ability.