For your focus issue:
If you are using auto focus, make sure your camera is set up to focus on the entire matrix and not one focal area. I would also set the metering the same way, and increase your shutter speed. Action shots are kind of hard to capture if you are using a focal point, because the camera is moving.
For your flash issue:
Diffuse the flash some how, it is extremely harsh. If you are using an external hot shoe flash, see if it has a filter slide in it. I just took a peice of white copy paper, cut it to the filter size, and slid it into the filter slider. It works perfect. Now, if I need a flash, it gives the area soft light instead of hard, direct light. If you are using your pop up flash on the camera, tear a peace of CLEAN white T shirt off, and wrap it around the top of the flash and tie it down with a rubber band. Depending on how strong your flash is, depends on what thickness you need to use. On mine, I have to double layer it, because the flash is HARSH on my cam, so I fold the T shirt over and put 2 layers on top of the flash bulb. Oh yes, and make sure not to have any wrinkes in the T shirt piece over the bulb, it will mis direct light in your shot.