I'm pretty sure you're taking the wrong direction here. I don't think you realize the amount of work needed to implement collision detection. I'm also convinced that the built-in collision detection in Unity should satisfy your needs. A couple of questions:
- Are you using a mesh collider for your dynamic objects? If so, do you really need that? Character's colliders are usually capsules or sphere for performance reasons.
- Did you try to set this option CollisionDetectionMode.ContinuousDynamic to your fast moving objects?
If you really think you should rewrite the collision detection code, then good luck. The book you want to buy is a great reference. You can also find useful information and code samples there: http://www.geometrictools.com/.