Hmm... I think Magic should be allowed, under strict restrictions... e.g: No planetary destruction unless given special conditions, modifiers, or other abilities such as a mega-structure that amplifies the magic at the cost of a mass of resources to construct the mega-structure, lots of time to cast the spell and power up the mega-structure, and LOTS of energy (Kinetic, heat, electricity, e.g) to use the mega-structure. OR: Greatly limit the magic to things like targeting a small group of people or objects to one person or object rather than something that can affect or destroy entire planets... basically, greatly limit magic or add severe costs to balance it. That way its not necessarily possible to power-game with Magic, and it can become a super powerful tool at a given time, with obvious restrictions...