then theres no use in devoting points into int nor finesse until you will use weapons instead of skills.
Its better to take basic summoning skills, invest points into summoning and use a bow for other effects while investing stats into either finesse/wits or go for wand that gives some skills for dispels and get a shield investing stats into constitution/wits.
Either way something should be affecting minion spell damage. While nothing does. And still Supercharge doesnt increase damage by 50%.