Frozen Orb's missiles' damage is stated in the skill description/character screen. Lets say your Frozen Orb skill deals 400 damage. That means that each missile deals 400 cold damage, regardless of what your Ice Bolt skill says.
Hard skills in Ice Bolt increase the damage from Frozen Orb's missiles. The synergies of Ice Bolt do not, however.
If you can't learn to do something well, learn to enjoy doing it poorly.