Here are my thoughts. I like all the photos, but here is what I would change if I could go back to each one of the picture and set up the picture. Obviously not something you can do and hindsight is always 20/20 blah blah
photo 1 Gang pic... I find my eye wondering around the pic with no real subject. If it wasn't for the story, I wouldn't know what you were trying to portray.
photo 2. Black and white crowd. Good photojournalist photo, but my eye is drawn to the black shirt guy standing with his back to you. I would like to see more faces, with the main subject the drummers in the center of an arc. You might have been able to capture this by taking a few steps to the right. I feel like I'm standing outside of the crowd instead of being invited in
photo 3 American flag. cool photo. I would suggest using a telephoto with a tight DOF, really focus on him and letting the people in the fore and background blend into a blur, also a quick sec later and you could have captured all of him.
photo 4 the car. Cool photo. Alittle center weighted, shooting tighter on the car with the main subject (car) off 1/3 to the right. The surrounding are alittle distracting.
All and all, good photo and you have a good eye