Besides, crit damage on a weapon is an amazing stat. If you have ~33% crit chance (simple to reach), 50-100% crit damage affix about 16.5%-28% increase in your overall damage output. If you also get an open socket and stick an emerald in it (50-100% crit damage), those 2 affixes together can end up giving you as much as +56% damage (assuming both perfect rolls). Practically, the damage increase will fall between 28% and 56%, but still, getting good crit damage is a major boon to your DPS.%leech is pretty much worthless for wizards, so crit damage.
I did something like that myself, the hierarchy seems that Sword > Wand > Mace/Spear > Dagger. Blizzard really overcompensated on making the dagger base damage low and its highest flat damage affix has notably less damage on it. Maybe with +flat damage jewelry it actually catches up. That said, the difference between all three weapons is basically within 10% variation. It's not enough to worry about unless you are going for a best in slot purchase for your weapon slot somewhere down the timeline.Some guy crunched the numbers (sorry I cannot remember the source anymore), but from the evidence given, even a moderate damage offhand is enough to make faster 1h + offhand superior to slow 1h + offhand.