While I approve of many classes being overall buffed using Revo-Classic mechanics. I think several of them are still outclassed in combat or any recognizable niche they may have been intended to occupy with their access to skills. For a good example we need only look at the Rogue class and their skills. While writing this post I am keeping in mind of future access and power spikes to Trans skills and for Rogue's, the use of Plagiarism which allows for the powerful Revo dominated Bowling Bash. Any changes I suggest will be isolate from Trans power spikes and focus on changes of underused or more niche skills.
Back Stab is a skill, that was in the past, a very powerful skill. But it was hampered by an incredibly direct nerf where it forces the enemy to face the Rogue. At 16 SP and 700% ATK damage at maximum level this is merely a defunct Bowling Bash. While I can appreciate it's potential power, I hope some quality of life change would be made such as removing the turning on strike feature or using the older version where the game couldn't recognize the back of the target and worked based off the target's last direction they moved in. Or even increasing the damage for this skill to be obscenely high and turn them effectively into one-shot assassins. Ball-parking the damage number at over 1000% assuming there are no quality of life changes, the skill would then rely solely on positioning behind a target and one shotting them.
Intimidate/Snatch is a strong utility skill which teleports the target. My beef with this skill is that at level 5 it consumes 40 SP for 250% ATK damage. A proper and respectful buff to this skill would be to obviously reduce the SP cost to something much more reasonable for a class that doesn't invest so much into INT unless they go MATK Plagiarism (which is laughable without Trans and when MATK is weak in Revo) and for it's purpose of utility. It might also do to even slightly buff it's damage to say 300% ATK for good measure to be more consistent on weaker mobs as a form of a 'free' flywing.
Raid/Sightless Mind deals a 7x7 AoE 300% damage attack with a 25% chance to Stun and Blind. Note however while the SP cost is 20, it must be used with Hide, making the SP efficiency worse than one would like. This is practically an AoE Bash in design - but obviously weaker than Bowling Bash. I think that being so similar to Bash yet weaker than Bowling Bash it should be brought up to par with 400% ATK, similar to level 10 Bash. Otherwise it's a fine skill, especially in combination with Hide and Stun to give it survivability for mobbing.
The next class I'd like to point out is Alchemist. Oh boy Alchemists, they're weak now for sure, until Homunculus and Trans get here and everyone starts salivating and crying about them. But an incredibly easy, and effective way to buff them in my opinion would be to just make Axe Mastery ridiculously strong, enabling what would be Battle Alchemists. While Blacksmiths have all their buffs, Alchemists have Axe Mastery - their only real combat skill, even if it is a passive. Buffing Axe Mastery is a great idea because it's completely seperate from any future power Alchemists will have while enabling them to actually be decent on their own using these melee-focused mechanics of Revo. The numbers themselves would have to be tested but I'm sure it would be easy to just ball park the number to something high and work it down from there. That or simultaneously buffing Blacksmiths as well by buffing Cart Revolution or Mammonite, the staple skills of the Merchant class.
For other classes, the only suggestions I can really see is maybe buffing Throw Arrow on Bard/Dancer to even be competitive with Double Strafe, otherwise MATK based classes like Wizard and Sage and the hybrid skill GC Crusader should be buffed across the board. Every other class I feel is quite balanced and has strong future prospects to ensure they still remain strong