The .chan format is just a tab delimited ascii file of raw sample values.
The bclip is a binary version of the clip format. The clip format is not documented, but its human-readable ascii and somewhat straight forward.
If you have a CHOP you can always edit its samples in the CHOP viewer.
This is done by locking it, and bringing up the 'Raw Edit Tools' (e) in the viewer.
Turn on dots (d) and you can select and modify ranges of samples.
Though the documentation on this needs to be added.
Editing a pre-existing CHOP in the keyframe animation editor is also doable.
There are no keyframes in CHOPs, so first you'd have to convert one using the 'keyframe -c chopname' command in tscript, or CHOP.convertToKeyframes() method in Python.
This will produce an animation component that you can then refer to in the animation editor.