So it's simply
slip edited clips you're talking about(?). You can bounce all the clips on a track to a single clip by
bounce to clips. IIRC you get an option to delete the hidden, slip edited portions in the process.
If you
bounce to track the material is copied on a new track leaving the original untouched.
You can normalize each clip separately, but there is no way to do it in one go, it must be done clip by clip.
If you normalize the whole track, normalizing will take place according to the loudest peak of the loudest clip, which
most likely doesn't give the result you want.
Have you tried evening the volumes with simply a compressor? It might work, depending on the material.
Just to clarify the terminology: A clip is a clip. A clip can never be a part of a bigger clip.