And here I was hoping for asking about balance between the various flavors. 

The shard scaling also.  If you wanted to just have a couple types or one.  You are most likely not going to get type that you want.

Agreed, spell scaling is going into stupid ends (Not watching the vid, just tried myself).

Sincerely
~ Kongdej

Is there a way to perhaps increase shard power via traits?  Like, take this trait and gain +1 shard power in all shards.  You'd have to make a kingdom and empire version of it, but that was going to be how I redesigned some of the magical professions, assuming this functionality is possible.

Huh? Nobody suggested a complicated system like this, but you are right that such a system would hurt the AI.

Yep the randomness of the shards and the shard scaling make the spell balancing more difficult, because the player does not know which shards he will get on the map and he must create his Sovereign before the game starts.

Changing the Path of the Mage to + 1 shard power in all shards is possible and in my opinion exactly what the trait should do, but i guess that the effect of multiple mages would stack and that would cause more balance problems.

Another option would be to reduce the impact of the shards. Most shards increase the base effect currently by 50 % and i would reduce it to 33 %, but the base effect should be increased first to make all spells useful without shards.

Heal (currently):

8 HP + 4 HP per life shard

Heal (changed):

10 HP + 3 HP per life shard

It should be a sovereign profession that increases shard power, and unlocks traits that give more shard power.  I'm thinking of calling it Archmage.  As you note, letting all mages contribute such a notable bonus would probably be overpowered, unless it only applied to their own spells.

Oh ok, i have sometimes the memory of a goldfish

Another option would be giving every faction a building (Tower of the Sovereign, minimum city level: 1) that can be build once per faction and grants + 1 shard power in all shards.

Go big or go home guys.  Remember Derek's motto.  Spells are overpowered just like everything else is overpowered.  Having said that, here's why spell damage isn't as overpowered as you think it is.

shards:  totally random.  how big of a map are you playing on?  what resource setting are you using?  how lucky were you to find more fire shards than earth shards?

evoker trait:  totally random.  how many quests and monsters and experience dealing objects in your world setting to help your heroes level up so quickly?  how lucky were you to get the evoker trait instead of spell resistance I and strength as a choice?

fire mage:  you picked "fire" mage because you totally wanted to see some serious damage so get on with it.  burn baby burn!

And finally, rumor has it that Brad is chuckling in his office which means he will soon teach the AI how to use spells.  Then when you cast 100 point fireballs (if they're not counterspelled), they will be returned as 120 point blizzards.  Now what?

Thanks for playing devil's advocate Trojasmic. Here is my rebuttal.

Irrelevant. One fire shard makes fire spells do too much damage. Getting two is a game ender. The problem is that evoker is balanced with no fire power. Getting just one is an imbalance. Getting more means killing most things in one hit, which leads to super fast leveling, which breaks the rest of the game. It happens on all settings to some degree.

Irrelevant. Heores on the lowest possible settings still level to the evoker trait very quickly. The only difference is getting it on turn 50 or turn 150. Either way the problem is there. Evoker is far more powerful than the other choices. Strength is essentially +2 initiative. Evoker is a massive damage boost to spells. Doesn't compare.

No, I picked fire mage because it is the most ridiculously unbalanced thing ever. I wanted to play a thief, but there was no option. Balance, baby, balance.

Wizard1200 beat me to the AI thing. He is right that it will just be two entities using an unbalanced system to wreck years worth of units and injure heroes. And the winner will be decided by initiative and fireshards. No thanks. Going back to my mod. 

well game need balance in every aspect this is just one of the many

like i said elsewhere i modded to have warlock 10%, evoker 10/15/20, and more end game itesm with a bit less of damage bonus

also a lot less mana discount in combat, mantle 10% etc

this is the way to go

I'll keep the devil's advocate thing going since you like it. 

What do you do when you bring your evoker fire mage to a tactical battle against my impulsive horse riding hero with charge and maul weapon?  You can't cast a fireball when you're dead.  Should we start a new thread about how impulsive horse riding heroes with charge and maul weapons are overpowered?  Or should we go back and review Derek's motto?

Now that you mention it, yes. That is the whole point of a beta and I seem to recall one such thread. Also, I have done some great work to balance Assassins so that you can't do exactly what you are referring to. Assassins use progressive poison damage and special attacks, instead of becoming horse charging crit machines. The crit multipliers are also insanely OP. Even on a crit, you shouldn't be doing upwards of 150 damage. And that is not even at a very high level. Add to that the charge and impulsive problem and we really have a mess.

It's fine to have things balance at a high amplitude, but then sometimes those OP options obscure the subtleties of the system. In my mod I have somewhere close to 6 strategies for leveling an assassin, while the vanilla can only manage the one. This is because I took a step back, nerfed the OP stuff and accentuated the potential of the path. Assassins can rush a mage, but they can't kill them before the mage has a chance to run or disable the assassin. 

Go back and read Derek's forum post on this.  "Overpowered" is a term that Stardock (i.e. Derek) actually likes to hear forum users use.  Kraxis gets to start with 1000 gildar and recruit all heroes.  What?  That's overpowered!  Procipinee can create outposts with spells and wears a crown that gives her enchantments with no maintenance cost.  What?  That's overpowered!  Tarth can move through forests and swamps and are invisible to monsters.  What?  That's overpowered!  The Dirge of Ceresa?  Overpowered!  And somebody just might get lucky enough to be a Warlock + 50 %, Path of the Mage + 50 %, Evoker + 75 % (25 / 25 / 25), Staff of Souls + 25 %, Ring of Mastery + 25 %.  What?  You get the idea... 

Of course, I'm just playing devil's advocate.  I don't really believe any of this shiz.  I say nerf the fire magic a little bit more.  Fire magic has already been nerfed a little bit.  It used to be the only thing I would take, but now I'm liking Air magic for haste, tutelage, and tornado.  And Earth magic for enchanted hammers, stoneskin, and tremor.  And Death magic for blind.  And Life magic for shrink.  And Water magic for blizzard and tidal wave.