yes thats much better and now you can preplan (kinda becoming ASTs whole thing) stuff like setting up a 10% damage buff on say a SAM for their burst window or if you do want to cheese a tank mechanic you need to actually plan ahead now (i'd honestly push the mit down to 5-10% tho tbh) thanks to ewer and tower cards (you'd make ewer and tower effects permanent until used ofc). lady of crowns remaining a pure AOE heal but having a caveat for it being not the DPs card is also a good way to mitigate RNG cause you either get a maximum 60% bonus potency lord of crowns or an upgraded lady of crown that also deals damage (although it could be debated on which card deserves more damage since lord of crowns is only 150 more potency at max buff)
now onto new skills like comet. no reason for it to exist tbh it's just use immediately before combust for more DPS. now if you made it an ogcd that instead refreshes the DoT and provides a secondary effect based on how low the timer is that'd be leagues better as it would still keep you to pay attention to the timer and reward riskier plays if the DoT was for example about to fall off during burst windows without just adding more damage. we wanna kinda keep WHM as the DPS job and AST as the buffer job think MCH and BRD for example. imagine if you will if at 3s and below if you use the oGCD you get a temporary tower/ewer effect for all nearby teammates. this would help you still get use out of the effects even if you got bad RNG and it affects everyone so unless you draw an ewer or tower all other cards are usable with it.
the issue is we don't need more buffs for DPS and more DPS we need more interesting interactions within our own kits like for comet giving out tower and ewer effect to all party members you notice it's not just a DPS increase but actually melds well with what your kit specializes in. it's why sleeve draw as much as i disagree with it was good cause it interacted with ASTs core mechanic and made it interesting/feel better.
just an ending note change arrow the only caster that would even remotely benefit from it is BLM. sadly every other caster is already lower casts or have so few actual long hardcasts (SMN) that it'd basically be wasted even when astrodyne did that we figured it up at most only being one extra malefic per use which isn't the greatest thing i'd instead focus on arrow being a GCD reset card (yes ik it would be difficult to balance but it's RNG so you're always gonna have "good" and "bad" cards) plus it wouldn't benefit from ewer and tower so it's already at an disadvantage there as well