You have to try again the new platforming zone! Next run you'll beat it for sure
Also, I guess you already know, but for new people: At 10:55 you can double click and check what is in the 2 smaller compartments to the right of the big one
Dont forget to double click on everything
As little as you seem to take hits I'd bet you could get away with less armor. Have you ever tried a helm/breastplate only (maybe with gambeson/leggings) challenge run type thing?
Good level 4 run.