Classes do nothing but give stats and perks, it's powers and equipment you focus on and the braindead attacks I use are usually grease + fireball or wide sweep + song of storms.
Kiyoko is hated on this thread but I find her third set decent.
As I agree that the skill tree is underdeveloped and needs a complete overhaul. There are some things that are salvageable (perks and stat building) But yes, classes means nothing.
Kiyoko's 3rd set is what made her a good support and her script focuses on you. About the lore: Is needed to revisit and scrap al sperging aspects of ToBS (many if not almost everything from 2nd paragraph is clutter). The kitsune can be modified as lore friendly (the setting is OK imo, but badly developed) And the wayfort seems that is taking the wrong direction.
But returning about the Kitsune I could take them as a stranded colony from the gods war (the one whom could be presumably lost from the Old country) From there is needed a revision (the sakura den is basically a beacon of "what the fuck is this" that can break the immersion and lore) Could be modified as a more traditional colony and those kitsune become less "weebified" as a way to develop on the harsh condition of Sky-marches. Also modifying some ofwhat they are really. From husks to life force vampires. (more like the youkai they really are) and making Keros a bit more known as "trickster and sexual affairs" (mallach can fuck off as a slaaneshi knock off).
After that make the Champ a real benefactor for them stablishing relations with the colony and after freeing kiyoko have the protection issues for you (You are the owner of those lands aren't we?). The
most important part is modifying or deleting Kirito Sperg McNipples. Adds nothing to the plot and will not be missed as is, Add quest for the marriage of your daughter (
THE NINJA WAY) and branch some classes from your contact with the Kitsune Village. (ninja, samurai, general). The next is making the bunch of kids you made an asset from workers to actual soldiers (They have your skill sponge perk) and Taking Kinu on a more suitable role as head and caretaker instead a maid (As well to rework hime-kinu as more an strategist and administrator than welll... A maid.), that could include peasant kinu as more a companion like character (branching a quest to fix the relation with her mother instead a marriage) and pulling out from the shadows Aya and Asagiri with actual development.
EDIT: As well a nice way to grind and make worthy the classes is adding class locked choices and class locked lore pieces.
As example:
-Berwyn can only open to you if you are a mage
-Brint Macho (Gym) scenes are warrior locked (and its branches)
-Add sparring sessions with Atugia (Under developed character imo) Which are warrior locked
-Quinn can teach sexhex magic (Lust oriented Black mage and locked to the min of 30 corruption)
-Quinn can teach Thief skills and hone your agility
- Some parts of the main story being class locked (random encounters, dialogues, etc.)
-Relegate Caith as just a fucking support role and
OVERHAUL her entirely (FFS)
These are small points to fix the kitsune and to better integrate them into the lore of the game.