first impression: good or bad vibes at first glance? 
i'm hit by a blast of red textures and multiple layers on soft light, which is pretty epic, but a little too vibrant. near the bottom of the poster, my excitement lessens. i'll explain more about that below. 7/10

technique: are awkward blending and rough cropping visible to the eye? 
the green circles below are the sections where the cropping could definitely be improved. the lights on the upper left corner look awkward and out of place, so that should be blended out evenly. there is gray fuzz on the upper onew's shoulder so either you crop that out neatly or reallllyyy carefully blend it (i would choose the first option). the cropping on the lower onew it too obvious and jagged, so if you would prefer not to smooth it out by cropping, blend it slowly into black or gray. the same goes with HIS left arm because the flame seems to be mixed with his jacket. these are only very minor problems, though. 15/20

resources: did you just slap some characters on the canvas and get it over with, or did you use appropriate stocks and textures? 
you used an adequate supply of textures, but the whole red effect is too vibrant for the viewers (lol it's ironic i say that because most of my graphics burn out people's eyeballs) you overdid the flames a bit, but the message was sent through that he was a pyromaniac. the scan line textures are unnecessary, but the rest i'm fine with. 16/20

composition: does everything flow together neatly and is the whole thing balanced? 
this piece is pretty balanced, but the overall effect looks awkward with one onew randomly sticking out, so i would blend his legs more. the texture balance is good, but for the color balance, i would make sure that the faces are set at the same curves. for the left onew, his face is brighter and harder to see than the others so i would have erased that part/excluded it when you added a soft light layer or changed the levels/curves. the text isn't balanced because it has a curvy effect, which is not needed. make it straight for more appeal. there's already a lot going on in the poster. the bottom movie credits aren't readable and do not contribute much to the poster in whole, so delete that layer. the colors are way too vibrant and so the best way to calm it down is by desaturating the poster. 11/20

typography: font and font placement is huge for sq. 
i really like the font for "Pyromania" at the top because it's nice, simple and elegant and does not add to the general messy scheme of the composition. however, some parts aren't readable because onew's blocking a few letters. the second "Pyromania", near the bottom, has a problem. THE FONT. I would try to stay with one or two fonts for every poster and you already used three. In my opinion, I would NOT do all that fancy-schmancy biz with the title and keep it the same as the quotes, maybe just change the color for emphasis. try to keep it block letter, simple and legible. 9/20

theme/mood: does your graphic actually fit the mood of the story? 
it fits the mood just fine. it's just exploding on your face a little and some areas are too bright for an angst-dark poster. 9/10

total: 67/100= 67%

this is what i think these tips applied should look like:

this is for educational purposes. please do not claim as yours. also, this may not be the best version of this poster because i had to work with an already-made poster.

notes: i'm sorry if i was harsh in this review. as they say, no pain no gain. i hope you've learnt something from this! please drop a comment saying you've read this review and it wasn't for nothing. if you have any questions or concerns, go pm me :)