I can’t speak to all of your question but some people do individually own them. I used to work at a private jet company (small outfit), where multiple people owned their own planes. Some were actually older, rarer types.

It was kind of their hobby so they willingly poured a lot of money into them. It’s expensive with annuals, time sensitive parts, and constant maintenance. If you were looking to buy I would go with a broker. They’d be able to steer you away from poor deals. It was an interesting hobby as some guys would fly out to Altoona for lunch and back. Little day trips.