Spoiler-alert in the spoiler tag as it's not just for the first episode:
: Right now there is no real plotting going on. We basicly get no view from the "front lines" as far as progression goes, most of episode 1 just gets lost in the time skip.
As far as the thing with the flashbacks goes: The anime is based on light novels, in those the timeskip happens aswell but everything we have been seeing as of now are flashbacks that get told in diffrent parts of the volumes, the anime takes all those and presents them in chronological order (that's what I've read, didn't read them myself).
So basicly instead of getting to know more about the main plot we get these side stories. Things like what happens to them IRL (which is told early on in the LNs) are left out and were left to belive that he, the "beta player", is obviously talked about as the black swordsman on lower floors and one of the highest leveled characters but still he hangs around so much? Totaly fits the selfish beta tester type that even has time to show a noob around on the first day.. duh :D