Definetly. All those abilitys/klasses/skilltrees would (in my opinion) not fit into a game like Oort. This could turn the Oort interface into something like that (since you mentioned WoW i´ll post a WoW picture as example):
(please note that i´m also reffering to an overkill with that picture)
Now to my suggestion:
Since Oort is not as focused on the fight mechanics/character progression as traditional MMO´s (which basically are all around these systems, while Oort also offers building, exploring,…) I want to compare to a game that is also much about exploring: Skyrim.
The battle system is quite simple yet really fun and strategical.
Since this threat is about skilling/abilitys and not the combat system i will just briefly summarize the combat system for people who are not familar with it.
You have 2 hands that you can separately equip with weapons/spells, each bound to a mouse button (if you hold a mouse button down you “charge” the attack).
Additionally you have one spell(shout) wich is bound to a key on the keyboard (“Y” by default).
Since you only pick your race and no class in the character creation (perfect in my opinion) you had a perk system to customize your character wich looks like this:
Each bright star at the end of a line represents a skilled “perk” that gives you a passive(there a also a few active) bonus. (There are plenty of “skill-planer” on the net if you want examples of what perks exactly do)
With each character level-up (by killing mobs/ questing) you gained a skillpoint to spend.
What perks you can unlock depends on how high your skill in the depending category is.(increased by simply using that category, for example fighting in heavy armor to increase your heavy armor skill)
Now to the “shout”(spell):
Your “shout” is a powerfull abillity with a quite long cooldown (~30s). You could choose from a variety of spells to get one that fits your playstile the most (charge for warriors, a short cloak for assasins, freeze enemys into a block of ice,…)
By killing and absorbing the soul of a dragon you got a skillpoint to spend into improving your shouts (Titans?)
New spells were earned by clearing specific tombs (Oortian ruins?)
I dont want to say that the Skyrim skill system is perfect (for example the skilling of crafting perks was quite a pain) or that Wonderstruck should copy it (which they certainly wont do) but there a definetly many great ideas that could be used for Oort.
NOTE: No, I´m no Skyrim fanboy but in my opinion Skyrim has the best fitting combat/skill system for a game like Oort. (simple enough for a voxel game yet complex/stategical enough for a mmo)