Indeed, some of the more useful skills are of the mage and survivor paths. I'm not saying that the warrior skills are useless. It's just that there are much better skills to pick if you choose the ways of the wizard and survivor.
However, one must not underestimate Augment Defense. This is probably one of the very few warrior skills that you want to max out. Of course, you can always argue that you can get high defense by pumping agility. But if you have all the means, why not push it as high as possible? Some of the higher level enemies can hit hard, and this skill at least ensures that you don't get hit that often.
Or if you like to be a ranger, get a nice bow and max splitting arrows. Seriously, this is an excellent skill. You'll be suprised when you see this skill in action. It's efective against mobs or single enemies. If you know how to position yourself well, all five arrows will go to one monster, causing serious damage.
Weapon expertise is also useful. Other than that, I can't think of any other useful skills in this path. You don't really need them to be effective.