I think the second one is really good, the composition with the flag flapping and the trees meeting up is very strong and frames the skier well, good choice and angle on that one. I find the rest are good images, but are very similar to many other sequences and still shots that you see of skiing or rollerblading, where they are mostly about documenting the action.
2 it seems like you are focussing more on the foreground than the skier, the framing of the flag and the trees is kind of nice, but by focussing on the foreground the detail of the snow and the flag is kind of distracting
3 isn't anything special for me, i'm not really a fan of the angle, try moving around a little more and capturing more skier
4 is cool, but i don't think you need that big blank space on the right, maybe try cropping that in a little
good stuff though, keep shooting
NS is like your family. It's dysfunctional as hell but you still have to love it.