Well I will tell you this.. Elves are ALWAYS a great thing in my book~ :P

Mages in WarCraft run a gamut of specialties, with most combat spells involving fire, ice, or pure blasts of arcane energy, but are not limited to those, that's simply a game mechanic. In the tabletop RPG they had access to all the "normal" range of D&D spells, except Necromancy and higher level Conjuration spells, with those being reserved specifically for the illegal practices of Necromancers and Warlocks. Conjuration in WarCraft is almost exclusively related to summoning of demons, and demons in WarCraft are no joke, they are destruction incarnate and just want to watch the world burn.

As for other things: I highly suggest downloading the trial version of WoW and playing through the Blood Elf starting area (play as a mage!) it will give you the best idea of the current struggles of the Sin'dorei people and of the general design aesthetics of Silvermoon and the nation of Quel'thalas.

Finally, perhaps go full "this is a separate version of Marcella"? As in, this is a Marcella that grew up in a different time, she may have similarities to original Marcella but they are distinctly different characters. (Also allows you the fun of self-cest down the line if they ever cross paths).

Yesssssssssssss.

Helen will help you learn how to be a good elf!

Oh I have no doubt about that