While I don't exactly disagree with your overall point, fire I vs light I is arguably one of the better balanced parts of new game+, with the former being cheaper to cast, having more base power, being useful out of combat, and being gated behind Charlotte not being in jail(+1 day, 400 gold, lewds, or a 14 day wait) whereas deliver medicine is basically a freebie and light I is mostly useful for advantage.
Fire I also gates workshop level 5 if you have access to the refugee camp, which can translate to an extra ally level when clearing the Northern mine vault and festival of greed. This mostly impacts lower difficulties and early parts of the game where allies are quick to level.
More egregious are horror I and radiance I. The first only costs 10 points in new game+, is practically unobtainable during pure runs, and gives you a low-mana way to trip up enemy casters for defensive builds. The second costs 35 points, is pretty much unusable in chapter 1 due to its mana cost, and mainly serves to save(an admittedly large sum of) money unless you very specifically intend to chug another energy potion or two on Belphegor.
Another thing is the stat crystals having the same cost for all three stages. Changing something like a 5/5/5 cost of ATK/MATK to a 4/5/6 for +1/+2/+3 would increase the temptation for higher-score players to downgrade starting bonus stats for the sake of a skill pick, make the weaker tiers more accessible for low-score players who need that boost the most, and brings it more in line with the chapter 1 experience of escalating workshop prices.