I've found that the only time powers are really "overpowered" is when people can chain them. For example, being able to keep up feedback pulse or reverse shield polarity is absurd.
How should this be fixed?
Limit bridge officers to only being able to learn 1 of each skill. Don't let them have feedback pulse I and II. It just makes sense. You'll still be able to have 2 of the same ability if you have 2 bridge officers, so it shouldn't be a huge nerf or anything, but some of these powers just should not be allowed to be chained.