Awareness potions, works for DoTs or DD spells only?

Does anyone know if the spell awareness potions which reduce mana cost (eg. heat awareness III, magic awareness III etc.) works for DoT spells?
Tried to find information on them but came up nothing.

Works for all spells except CH afaik. You can just google it also

Does the awareness effect stack with everything?

Yes, and no. It stacks with your mana preservation gear.
You can use various "focus" potions at once too (beneficial duration, beneficial mana pres, etc).
Obviously they don't stack with different ranks: Beneficial rk2 doesn't stack with beneficial rk3... etc.