The difference is in the mounting brackets that come with the camera, outdoor comes w/ curved and flat sticky mounts as well vented helmet mount and head strap, motor sport comes w/ the suction cup mount. I went with the outdoor and bought the suction cup mount later. just my $.02.
It does not have a zoom. It is more geared towards wide shots. You can pick your format and that does change the width of the captured image, it's explained in the manual. There are 3 settings but they are not available in all modes. Full, Medium and Narrow Field of View, Full is 170 degrees (very wide), medium is 127 degrees and narrow is 90 degrees. In the sales lit this is referred to as FOV or Field of View and that's essentially your zoom.
If you buy the add on back screen and practice using it at home I am sure it would be fine for your trip. It is small and light. But, there is no lenses or zoom so it is really simple. I would rather get a Nikon D7000 or some great camera that also does video.
Yes it comes with all outdoor accessories that are: vented helmet strap, head strap, 2 curved + 2 flat surface adhesive mounts and a 3 way pivot arm. It comes with the vented and sealed backdoor. I had the same concern but trust the add you wont be desapointed.
I have not, I have used it for whitewater kayaking and swimming with the kids, but I have seen videos of people sky diving so it is something you could do with it. The only thing you would have to do is mount the camera to a helmet or use the provided wrist strap. It does come with the mounts that will stick on the helmet that you are using, but I would strongly recommend some kind of leash that is attached to you in case it were to blow off your helmet. I have not had issues with that, but I did have an issue kayaking and accidently hit the camera with a paddle and did not have the leash attached and lost the camera, but that was my fault not the camera nor the stick mounts it comes with.