Don't forget agility, especially for the melee character.
Shaman magic spells are available in act 2, which are much more powerful than the spells in act 1.
Two handed melee skills are available later in act 1 from one of the soldiers in the citadel, or from Olaf in the battlefields.
There is a filter icon on the skill window, which will let you toggle between showing the skills you know and all skills.
