Hello dear Funcom!
I hope this wasnt suggested yet. 
Please pardon if it already was, I have a rather limited amount of time available to me.
It has been a while since users were daydreaming about the implementation of magic into the game and it got me thinking about a lore-friendly implementation solution which I would like to share with you:
The solution which came to my mind is, that there would be classes picked on start but suppressed until the user removed their bracelet with The Keystone. This would provide us with lore on how the giant kings were able to suppress a huge amount of slaves, as the bracelets thus depraved the humans of their powers, giving the giants a non-negligible advantage.
Naturally this would need to change the way several things work - using the keystone could no longer “delete” the character, but it would enable us to walk past the green border (for all the good that would do) and use the new skills as desired (and trained). When a player would walk past the border a prompt would come up offering to wander out of the exiled lands and if confirmed the player would need to confirm another prompt “this will delete your character. are you sure?”. I always felt the Keystone was a bit of a huge effort just to delete your char when it could serve a better use - this might be it.
Also Maprooms would need to be altered, perhaps an upgrade to the maprooms themselves (maproom lvl 1 and lvl 2) or through the crafting of an item, which would serve as a subsidiary to the slave bracelet. Naturally, removing this subsidiary would no longer kill the player. Also - magic characters would be able to open portals to bound places, either the map room lvl 2 or a “teleportation pedestal”.
Another thing would be an increased level cap, where we would gain experience in the feats there currently are and, through unlocking the players class, would gain like 30-ish more levels where we could upgrade the attributes, feats AND the new skills. Each level would give the player skill points they could invest into upgrading their new skills/spells, with skillpoints gained even while the class is locked.
I hope that was all the ideas Ive had on this and am looking forward to your (and the communitys) oppinion on this proposal.
Thank you for your hard work!
Derian