And on the same lines, would like to see different ways of recruiting these unique units (I think you yourself mentioned this).

Was there some talk about conjuration spells in the works?

Oh, right... I too look forward to "mundane spellcasters"

I know that I've seen both items (cloaks) and spellbook enchants (ie anointed by fire) that give a champion to cast a spell normally they wouldn't have. But haven't hit anything to give mundane units caster abilities.  There are equipments that you can have to add magical components to attacks, but that's just a bit of fire damage, etc.

The description of Gravewardens in the faction preview post almost makes it sound like they have spells, but I haven't gotten them in the game to see if they do.  I doubt it, just think the wording there might be misleading.  Some of the recruitable monsters might also have spells, haven't checked that either.  But some things like some trolls have spells, so its not out of the question that those special units have them.

I'm not sure if "mundane" casters really fits the game lore, but even baring that, I'd like to see traits that mimic spells, arrow barrage instead of fireballs or bandage wounds instead of heal spells. I'd definitely want it to be really pricey and maybe have a bigupkeep to keep it balanced.

I agree.  We could use these "spell like abilites" to further customize units.  It would be great to give units a healer's pack that let them heal or remove status effects so many times per battle.  On the damage side having an alchemist's kit could add some elemental damage attacks to a units repretoire.

Definitely. There's some talk of that in the city discussion thread, and there ARE some buildings/spells that provide boosts to units constructed, they're just mostly (entirely?) passive boosts to stats. Some active abilities would be a great addition.

Maybe spell-casting units would require mana to be produced - like they are being "imbued" by the sovereign, even if remotely.