Some theory-crafting about the structure of the skills:
Every skill and attribute in this game was made taking in consideration its rank and class cicle. By removing those elements, they’ll need to find a way to balance and equalize their overall power and value, either by increasing their drawback or , the least likely, reducing/removing their power. I say least likely because having the feeling of becoming weaker or having a favorite skill being nerfed is something that brings a very strong feeling of dissatisfaction for the players, which IMC will probably try to avoid.
That being said, I believe that a neat way to balance C3 vs C1 skills is to invert their maximum skill points and skill point scallings: C3 skills would need 15 Sk.P to reach maximum level, C1 would need 5 and C2 would be the same. This way C3 skills can keep their power with the drawback of requiring more investment.
About the attributes. I believe that many attributes locked behind cicles will either be replaced on their skill’s basic function (like the old cast time reduction attributes) or they will be nerfed, since there’s no much solution for them because the investment isn’t Sk.Pts, but rather money, and putting too much power behind a money wall can be problematic. For example, Dragoon Dragon Soar’s Ascension attribute allows the skill to deal double damage by doubling the amount of hits, and it’s a reward for getting Dragoon C3. With this new equalized class system, there’s no place for attributes like this I believe, since they would be very problematic for the class’s balance. A solution for this would be keeping the attribute but nerfing it, like reducing the total damage by something like 40%.
About buff skills. I’m really like those, and I find them class defining skills: Deeds of Valor, Finestra, Quick Cast, Quicken, Trot. But they will obviously need to be readjusted, since they will become much more relevant. A good way to balance them is to make them switch (on/off) skills and reduce their power slightly. Maybe decrease their drawback as well to compensate, or turn them into class attributes, I’m not sure.