Answer from my experience playing wizard for 1 month.
1- Wich weapons have the most hight DPS ?
I think it Staff.
2- What is the difference between an Archmage, an Elementary mage and a Spirit mage and who have the most higth DPS ?
Archmage focus on power damage.
Elementary focus on boosting element damage.
Necromancer focus on summoning.
3- And what is the build of the 3 (or 4 ?) different type of wizards
Depend on you. what you want that what you build.
Since u ask what the highest DPS… i think you want to build power damage build. if so you can check here. my build. my build not perfect but it do well in floor 400+ with damage up to 900m.