Hi Dominikas,
There is a book titled "Essays in Evolutionary Astrology" where in the chapter "The Planetary Method of Evolutionary Chart Analysis" goes over the questions you are asking. That chapter is an old JWG lecture he gave.
That is where I would start, if you don't already have this book.
Here is a little from that chapter in the book regarding the Sun:
" ....the Sun specifically correlates to how we are integrating and giving purpose and meaning to our current life experience. So in essence we are describing an evolutionary transition in our A B list (Pluto, the lunar sn, its ruler, the moon, and the lunar nn and its ruler, along with the PPP), an evolutionary transition from past to the current life. The Sun is now going to show you how that is integrated and given purpose and meaning in the context of the current life". -JWG
The Sun is a filter for the chart, every experience that you have will be filtered through that Sun in order to actualize the bottom line of your or anyone's chart.
As an example, I have the Moon in Libra in the 6th and a Sun in Capricorn in the 9th. Every emotional experience I have had that has been extreme (Moon in Libra) or that has been about improving upon these extremes (Moon in the 6th) has been filtered through my Sun in Capricorn in the 9th. Essentially, I have been actualizing my chart through becoming my own authority and reconnecting with my authenticity and personal truths (Sun in Capricorn/9th) and have learned how to do so through the extreme experiences of abandoning myself in the past (Libra Moon in the 6th).
This is to just give you a little bit of an idea of how the Moon and Sun work within the Pluto Paradigm without going into my whole chart, as that is not part of the rules on the message board. Hopefully that simple example helps though.
Maybe utilize a chart of a well-known person on this thread so that you can practice chart interpretation and receive feedback so you can expand on your understanding. That way it's more tangible and it also gives others an opportunity to learn from it.
Much Love,
Jordyn