Dave:
Not sure if you shot these RAW? My suggestion...shoot RAW, ignore all modes on camera and shoot in manual mode. Start with f2.8 on your lens and 1/400 shutter (good enough for these little guys) and then adjust your ISO so that you are showing at least 1 stop overexposure on the little meter at bottom of viewfinder (+1). If your light is good, you can bump up shutter speed, or decrease ISO to reduce noise but try and ensure you are always at +1. If light is crappy, then boost ISO...never drop below 1/400 shutter for hockey action. Use AI Servo, Center point (or zone on 7D?) focus. Use an Auto White Balance (AWB) or shoot a custom white balance using skated on ice as your reference photo (see manual for how to set this). I find AWB works 99% of the time just fine.
In post processing, watch your cropping, eg #2 has too much dead space at bottom, #3 has too much at top. Also rotate your images to get horizons correct. You can use the joints between boards or the metal stantions between glass panels as vertical "plumbs" to help do this.
Please feel free to look at my most recently completed set of little guys hockey HERE
for some crop and shooting ideas. All shot with 70-200 at ISO 2500, f3.2 and 1/400. Had to boost exposure a tiny bit in post, as well as crop all to 8x10 dimensions, a little bit of sharpening and noise reduction and some increase to blacks setting.
Keep shooting!