I believe that if we would carefully apply the distinction between transparency and opacity to the different layers of the human self-model, looking at self-consciousness in a much more careful and fine-grained manner, then we might also arrive at a new answer to your original question: What a "first-person perspective" really is.

The conscious experience of being a subject arises when a single organism learns to enslave itself.

Whoever loses the capability for inner silence, loses contact to himself and soon won't be able to think clearly any more.

I believe we should really take our own phenomenology more seriously. What a good theory of conscious must explain is the variance in this subjective sense of realness: There clearly is a phenomenology of "hyperrealness", for example during religious experiences or under the influence of certain psychoactive substances.

I could never understand how someone would embark on their life without having first confronted and clarified the truly fundamental questions.

Only as long as we believe in our own identity over time does it make sense for us to make future plans, avoid risks, and treat our fellow human beings fairly - for the consequences of our actions will, in the end, always concern ourselves.

The notion of a conscious model of oneself as an individual entity actively trying to establish epistemic relations to the world and to oneself, I think, comes very close to what we traditionally mean by notions like "subjectivity".