Ambassador

I completed the map with the Hero....
Question: Are Berserk and Vampirism forbidden for Varen, or is it random?

All spells are allowed on this map. There's no point in banning "Berserk" because there's the Dwarf Shield. "Vampirism" is found in one of the temples along the way to the first Dwarf town. You probably just missed it. The map is very well thought out, balanced, and polished. All the apparent randomness is actually intentional.