We are definitely seeing very different patient populations (I'm a CAP but also see younger adults, usually higher functioning) but for most of the categories you mentioned, the patient is pretty limited in what they can communicate so I would assume you need another person present (family member, guardian, etc). I could see this translating into some family-based type of psychotherapy where you are helping the caregiver/family communicate with the patient and make treatment decisions. How you define that is up to you (I think supportive/expressive psychotherapy can encompass a lot of different things).
To each their own but I think it's pretty easy to justify therapy add-on codes because the burden of defining therapy is on us. Insurance companies don't know the difference between psychodynamic, CBT, MI, DBT, etc. Sure, if you are trying to be as "by the book" as possible and only thinking of psychotherapy as formal, manualized/evidence-based therapy that will limit your options. If my patients are getting better and I'm spending quality time with them, that's worth something - to me, that justifies a therapy add-on code. We're working in a system designed to maximize our efforts and minimize our compensation, so I have no problem finding creative ways to offset that.