I think it's nicely done, face / gloves /graffiti and arm band make it look like a brand new platoon member.
I wouldn't worry much about the graffiti you put, at this scale you did pretty well, though I would have added a little white "make-up" around the "Big Bad Wolf" to hide the contours you cut, to make it look like a cartoon explosion or something like that. I would have dissimulated the hole in the shoulder armor too, (looks "Hicksy").
I guess I already told you that, but if you find the graffiti not satisfying, you may try model kits nose art decals (1/72 scale), they would fit right on. You can also consider customizing or accessorizing the helmet in the style of Full Metal Jacket
.
Good job anywway !