MikeAqua: I would add to your process before step 1 a clinical psychologist's opinion that the person is emotionally/mentally up for seeking, finding and retaining employment. It's waste of time if they are unemployable.
The problem with the suggestion that you don't bother improving someone's mobility if they are unemployable is that there are other benefits of improving mobility. People with increased mobility take fewer drugs and are less likely to clog up hospital beds. They may need fewer tax-payer funded support services. If the person becomes disabled other family members sometimes need to quit work and go on benefit to care for them. Surely it would be better to help them to look after themselves than to ignore them until they become a drain on the healthcare system. It's cheaper to provide services that keep them out of hospital as long as possible.