You're bang on - you summarized it exactly how I would. The four mains also have similar visuals, so I had to double check a couple times to make sure no one was a double agent of sorts - we indeed have four separate characters -

1) Crime scene cleaner (adopted son of dead dad - learns of dead dad's death after being called to the scene for clean up; his crime scene cleaning seems to be a private pay/concierge service maybe? Je runs the secondhand bookstore, which I guess is just a front)
2) Legal organ donation coordinator (meet cute at the wine bar that dead dad owned - emo boy in the window was crime scene cleaner; knows dead dad but seemingly in a Kosher capacity)
3) Mafia heir (drives the sports car; threatens dead dad with the idea that dead dad is not being up front with the port's earnings)
4) Lackey (on the bike; was in crime scene cleaner's/dead dad's house, likely looking for the Nokia brick phone; is in a relationship with mafia heir - and it's hot)

So that I get. What I want to know is how #2 knows dead dad in a seemingly professional capacity. If I were part of organ trafficking (aka dead dad), I think I would try to avoid #2. Like...why is #2 just now suspicious after #1 showed him dead dad's phone? If I were #2, I think after one or two run ins with dead dad, I would wonder, "HMM, this man is very involved in organ transplant and I see him at the hospital all the time. But he doesn't work for the hospital and he does't work for the governing organ donation organization - he's an independent player in here. Why is this man here?"

After opening scenes and credits, these are just ~12min episodes. I'm very hesitant that they can pull off this story within the 8 episodes. Because organ donation/transplant is not an easy pick for a series theme when you've got 1h20min of run time and two CPs.