#1 - A few issues that bug me. First off, nothing is in focus. Not his hand, not his face, not his shirt. Rule #1 of portraiture is focus on the eyes and make sure they are RAZOR sharp. If the eyes are not the part that is the "subject", that is the part that needs to be sharp. His expression is... well, not exciting, not scarey, not mean... what really is he trying to express?
If you want anger, MAKE the subject express it!:
#2 - Back light is blasting away WAY too hot, and the front is IMHO underexposed. Those glasses are REALLY distracting becuase they are too big for his face and that reflection of the umbrella and strobe is not an attractive feature (please don't say you will address this in PS. Address it IN THE SHOT

). Zack Arias suggests something that I really like... "if you ever start to get lazy, or say that you can address it in photoshop later, give yourself a big smack in the back of the head...".
#3 - Pose is interesting, lighting just starts to get interesting but falls on it's face off into unattractiveness on camera right. I'd add a reflector to that side, pull the model 6-7 feet further forward and blur out that ugly backdrop. Ugh, those glasses are still there.
#4 - Lose the glasses, focus on his FACE not his feet. The personality of a person resides in the face (the EYES), not the traditional unlaced runners. I would have added a hairlight/rim light on THIS shot and done something about the unattractive material all over the floor.
Shows tons of promise... needs work.
