Some time ago, I've read IIRC that the Wizard had a passive that all damage taken was reduced to 35% of total HP, or something like that, what happened?, did they remove it?
No, that was the Force Armor rune on Energy Armor. They made it so that it would not absorb more than 100% of your total health for a single hit, so if you took more that 135% damage, It would deal the first 35% to you, absorb 100%, then deal the rest to you.
Did they remove a Wizard passive?