Been playing with both for the last few hours and noticed a few things I thought I should bring up.

Both classes have been mostly fun, but there are a couple of things that seem really unbalanced. First and foremost, as a main class frost-kissed is kind of underpowered and herbalist is abysmal, not in a skills way but based purely on stats.

Frost kissed has enough positives that having it equipped as your primary class isn't directly harmful, but having herbalist as primary is effectively suicide. The -2 to magic defense, -1 to defense, -2 to ruin, and 50% ruin weakness makes herbalist completely unable to take a hit from anything, which is a pretty bad trait for a healer to have. Furthermore, any ruin attack at all is nearly guaranteed death, as a decay from an enemy with 3 magic and 2 ruin skill is enough to do over 50 damage. While this would be pretty terrible for any class, it is especially bad on this one since it is unlikely that you'd be able to heal before your turn since this is most likely your primary/only healer. And even worse is drain. If an enemy hits the herbalist with drain the healer is downed and that enemy now has full hp/mp again.

The main issue here is that both classes have entirely too many negative stats. In fact, not a single base game class and very few modded classes have any negatives at all (out of my 27 modded classes, the only other class with negatives is the wizard from lumiest). Skill wise both classes are good, but I really don't see the reason for the terrible stats. Especially since you can just equip any other class as a primary after learning the skills and not have to deal with it at all, which is exactly what I did. After being surprise nuked by decay I did some testing to see just how bad the ruin weakness was and promptly decided to just throw my pile of 40ish essence stones at the herbalist to learn all the skills and swap classes.

Terrible base stats aside, both classes have been mostly great. Herbalist is honestly solid all around. I was kind of expecting to hate the balm bomb ability since it has both a long charge time and a long explosion timer, but if you just throw it out in the middle of the battlefield on the first turn it usually manages to do something helpful even unupgraded, mostly because it's a damaging and healing ability. Cryo bomb on the other hand does honestly feel useless. Between the cast time and the delay I've never managed to hit more than a single enemy with it, and the only time it even hits anything is when I push an enemy into the radius with wind imbue or gate: barrage, but this might just be a me problem. Also, Frost Smash feels weirdly powerful. It's currently dealing 16-20 damage per hit for me which seems a bit high for an instant cast aoe (stats are 7 cold, 4 magic, 3 shield btw, so I seem fairly weak to be putting out that much damage). That being said, I haven't raised my stats at all since learning it, so this may just be a case of high base damage with low scaling. I don't really know, since I haven't gone into the files to look at the scaling, but if it is low scaling you can probably ignore this.

(My only reference point here, in terms of other instant cast AoEs, is burning wave. Normally burning wave at this early in the game only does 8-14 damage, but it eventually scales up into the 25-40 range depending on my build and enemy resistance. So basically, it's hard for me to know if Frost Smash is really as strong as I think it is, or if it's just front loaded.)

Edit: Forgot to say this, if Frost Smash does have high/decent scaling I'd personally prefer an increase to the mp cost to around 13-15 rather than a nerf. While it does seem really strong for the cost, there are currently very few sources of instant ice damage and no instant aoe ice skills unlike literally every other element (other than life,but that hardly counts)

That's pretty much all the feedback I have for now, I'll add more if I see anything else that seems worth mentioning.