Sounds kinda interesting but do you want to adopt your system within the normal warcraft univers and without own content? Also does it sound like some kind of skyrim-system where you can finally skill up everything and this way become a high magican wearing plate armor and a two-handed sword. Or do you want to give a certain number of skill points for each level/challange so that p.e. the player has 100 points to spend for 200 skills?
Spells can only be learned if you have the number of points, for example intelligence and spirit necessary.It's the same for other weapons and equipment.In WoW it is unfortunately not possible because these points are awarded automatically, as well as spells wizards are all the same and only the equipment makes the difference.