1 - The cropping is a bit awkward with cutting off her feet and butt. Either show all of it, or crop tighter so it's more of just an upper body shot. Her legs form an odd triangle at the bottom which can be distracting. Also, the stripey thing in the upper left behind her ear is distracting.
2 - Random tilt is random. What is she pointing at? Did you do some processing on her skin? It looks a bit...flat. Should crop in from the bottom right, above the knee and closer to the elbow. The white area in the lower left is very bright and draws attention.
3 - Pretty standard shot against a wall. Looks like you just walked up to a cosplayer sitting and took a shot where they didn't even stand up. Or maybe that's the pose. I dunno. Harsh shadow due to mounted flash and cropped off foot make for a pretty bland picture.
4 - Nice shot, but it's so dead-on-centered. The ear is cut off at the top and there looks to be a house that's about to fall over in the top left? No matter, they're too busy kissing to run from the falling house. You seem to have lost a lot of detail in the white trim of the dress as most of it is blown out. I'd probably go low and shoot up. And probably shoot landscape orientation instead of portrait.
5 - The white of the dress in the lower left is blown out, but it does help you light up her face a bit, which is nice. What's with the random person in the background? Looks like if you moved 3ft to your left, you could've avoided that. Is that pole coming out of her? Is it coming out of the ground? I can't tell because you've cut it off. And she's wearing a rubberband for some reason. And she's not looking at you so there's no connection to the camera.
6 - Standard shot with wide aperture, mounted flash. Cool, the shirt and the thing have the same face... He's still wearing his badge. Might as well be a snapshot.
7 - Pretty much a hallway shot so I'm not quite sure what you were going for. The crop with the floating hand makes it look weird, like she's about to get hit with the bat. Look out behind you! Looks to be just mounted flash. Wide aperture to get rid of what you could from the background is good. Randomly tilted for no reason?