3 - I found it hard to have a sense of the ribs moving. I am much more conscious of movement in the pelvis and spine. Is it common to have some areas move but not others?

Yes. Trauma stuck in the system means parts of the system will be, well, stuck! This can include our joints, muscles, fascia and more. It’s quite common for the rib cage to be rigid and inflexible as part of a bracing pattern. Just keep it up and see if you can make the movements smaller and slower — I guarantee you there IS movement happening.