1) What is a "self"?
2) What is a "rich inner world"?
Define these and all your problems will go away. A lot of the time these terms are diffuse metaphors for a collection of things, so it's not surprising you can't find them.
> But did she really want to die?
This question, again, only gains complexity if you do not properly define what you're asking. What does "really want to die" mean? Create a definition, such as "a person really wants to die if they have been contemplating suicide for the past 6 months", and, again, your troubles disappear. If you don't know if Anna had such a desire for 6 months, then you're just lacking information. Nothing magical.
Philosophy, psychology, sociology, etc., are complicated precisely because they are vague enough fields that we still need to look at them through an intuitive lens a lot of the time, rather than the plain logical lens. It just comes with the territory. All it means is that we do not understand the field very well.
> But, as likely as not, Anna will be as unsure as anyone else about her true motivations.
This is not interesting. All that is happening here is that the entity in question does not have the hardware needed to understand its own hardware. A car doesn't understand itself, either. And humans do not fully understand their brain. Most entities are like this. This doesn't meant the car is magical and non-understandable, it just means there's no need to keep the hardware and its own understanding at the same level of complexity. Don't ask the car how it works, ask someone smarter, the human. Don't ask the human how it works, as someone smarter, the world.
> Why this sofa? Why Bach, not Brahms? Why this choice of career? Why children or not? Why evolution, not creationism? How does a bicycle work, or a violin, or a currency? And each justification can be buttressed with further justifications, caveats and clarifications, and each of these be defended further, seemingly without end.
I wouldn't mix these things up. Most people don't introspect much, and most people adapt to their environment. You will have a lot of issues socially if you don't have some simple answer to a question like "why this choice of career". You're generally conditioned to pick a tribe, so what you believe in can be important. Basically, these justifications have arisen due to pressure to create them, they're entirely unrelated to the "self". Saying "I don't know why I like this sofa" is not fashionable, even if it's very much the truth. And there's nothing wrong with that: we don't understand our hardware, which is fine.
Understanding of diffuse things like "currency" is, if anything, one of the more impressive functions of the brain that I'm not sure how long it will take for AI to replicate.