When setting up my melee Wizard build, I looked for a couple things:
1) Survivability was my top priority. As such, I decided Energy Shield and Diamond Skin would be mandatory.
2) Arcane power regen was another high priority; yellow runed Spectral Blade fills this role nicely.
3) AoE damage: I decided to take black runed Energy Twister and either Blizzard or Meteor. Blizzard for CC or Meteor for more damage.
As for the second question, I'll play this build through the easy difficulties so that I can get used to how it plays and it's strengths/weaknesses in different situations.