If the kids are running around like hell, as you say, then there is no way you are going to be able to light them. For that kind of B-roll just use a good lens and natural light. I edited a whole series of school videos that used this techinque and they still looked great.
If you are doing planned shots where the subject is standing still, then yes. Use the bounce. If you have an HMI or a powerful LED fresnel bring as backup incase it's a cloudy day... that is about the only way you are going to get enough light on a subject outdoors. A light panel isn't going to do much for you outside.
For regular b-roll I wouldn't worry too much about lighting, inside or outside. You have to remember here's no way they are paying you enough, nor giving you enough time, to properly light every b-roll shot. You just need a few kickass b-roll shots that are well composed with some movement to them and light the hell out of those. Those will be your signature shots that you can open with or whatever.