Nah ur crazy man. The flashback stuff is most of the Story. It shows us more about MC and everything that likely leads up to why he is actually going to Elysium. I will agree that some of the scenes can drag on a bit but the background of it all is important to the story.
So, guys... it's useless to discuss which part is cool and which part is just filler or meaningless, because that depends on each person's taste and perception...
For example, Sasha and Gigi are characters that I really like and I find their dialogues (usually) quite funny... HOWEVER, there are times when the part where they try to be funny goes on too long, and then it just gets tiring and boring... That scene where the two of them "roast" the MC, for me, is ZERO funny, and it's extremely long, tiring, that adds NOTHING to the story, doesn't entertain, doesn't lead anywhere... BUT, I imagine that there are people who liked it, right?
Kasumi... this "master" thing, for me, is already annoying. I think the complaints about it are almost unanimous, but I believe that there is a (very small) portion of people who like it.
So... it's all a matter of personal taste. some parts are nice, others are not, but let's remember that the game is being made for many more people, it's not just for me, or just for you, or just for the other guy