Finished my playthrough of your mod. In the end you made magic a little too good
My final party was lvl 70 Squall, lvl 65 Zell and lvl 50 Rinoa. I kinda regret not swapping Zell midgame for another magic user, since he basically never catched up to spellcasters in terms of damage, so I relegated him to healer role. Other characters were 30-40 levels behind, so were their stats, and to me it seemed like every point in stats mattered a lot more than in vanilla. I like that you made level gain much more relevant.
Now unto balance. There is a brief period (~second half of disk 2) where attack was preferable to magic, but after acquiring Cerberus and Alexander you can get Triple (via GF summon or High Mag-RF) and can supply yourself with level 3 spells from Odyne shop. With bosses being immune to Vit0, not even 255 strength and abusing of elemental weakness could catch up to 255 magic triple casting Meteor. I know you suggested to use Berserk, but it comes with the cost of losing control over character and it's not really an issue of damage on hit (it's comparable to lvl3 spells), but rather the issue of physical attacks being single hit, whereas milticasting can break 9999 damage limit. Limit Breaks should theoretically bridge the gap, but staying on low HP is risky and Aura is very hard to stock up (until disk 4). Considering how potent Triple and Meteor are, I think adjustments for refine formulas of Dragon Fin and Star Fragment are in order.
Auto-Reflect, Counter and Return Damage are really good, especially for a point in time you get them. With these abilities it's basically auto-win against Seifer and Edea.
Regarding command abilities, they are mostly like in vanilla can be easily substituted. Kamikaze got nerfed (and for a right reason, it was broken), Recover, Revive and Treatment like in vanilla are good only until certain point. You lowered the requirements of Whispers for learning Recover, but I still don't understand why it takes so much work for getting this ability at the point in time you can learn it. Defend being available so late made me never even try bothering with it. Bosses attacks are either AoE nukes or can be negated with Protect/Shell. Also by that time you are already such a powerhouse that in just a few turns of attacking you get a victory, so maintaining defense is not that neccessary contrary to how it was during Disk 1 and 2. The hardest battle on disk 3 was against beefed up Elastoid and Esthar soldiers during Laguna's flashback. Level Up/Down don't work on enemies I want them to (like Ruby Dragons or Iron Giants). Darkside being single hit loses to magic. Is there a way for this ability to break damage limit? Perhaps that could be the solution.
Disk 4 balance is heavily in player's favor. By getting to Ragnarok and playing with CC group you can get endless supply of Aura Stones (Gilgamesh cards), Megalixirs (Bahamut) and Holy Wars (Seifer). I don't really think player should have so much convenience for so little trouble. Is there a way to make CC group play only the cards you didn't get yet, but not the ones you refined? Because since you can get the cards again and again it doesn't really matter that the number of items you get through modding is lowered. If you abuse Holy War + Triple Meteor final dungeon becomes pretty much a joke and not posing any challenge at all.
Overall I enjoyed this mod. New additions in sidequests, much more desirable level gain and great balance during disks 1 and 2. It just needs a bit of fine-tuning on disk 3 and 4, because if player keeps up with the best options the difficulty drops down significantly.
