Questions about necromancer!

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1) How much damage do Skeletal Mages do with a maxxed Skeletal Mastery?

http://www.theamazonbasin.com/d2/forums/in...ST&f=53&t=29210
This link will provide you required info (although it compares skeleton magi in 1.09 and 1.10beta - be warned)

2) How does the damage from the weapon affect the damage of the damage of the Iron Golem?

In two words, it adds. I.e. take base 1-handed melee damage when possible (this is true for 2-handed axes, and do not ask why), else take two-handed melee damage, apply all +damage and +enhanced damage (if +damage is based on clvl, clvl of your char taken); and add it to base Iron
Golem's damage.

3) If lets say I revive the minions of a extra fast boss, do they stay enchanted with their enhanced speed?

Yep.