Regarding Winston, Julia and O'Brien's characters - Did they change? How were they created? Which were foregrounded and which marginalised?

In the beginning of the story, Winston finds his strength in knowledge and truth. He bucks the system because he discovers its corruption..... hence; his journal, affair with Julia, hiding from the telescreens, erasing things he's learned, and taking on an apartment. His intentions are good, but they are short lived, as the party breaks him through torture and his idealism crumbles.

Julia was always a bit of a rebel, but she wasn't a hard core rebel. Her main concern was satiating her sexual desires and taking favors where she could get them (Winston and Party members included). Her big change in the novel was falling in love..... love marked the end and ultimate betrayal.