I don't think the examples above are particularly good as we can only evaluate the effective skill level, without measuring the individual contribution of training and inborn ability. I'm no psychologist so I cannot say what is the current theory about it, but my personal experience of ten years as a professor tell me that characteristics have little impact in the effective level, if any. No doubt characteristics are fundamental to determine the speed of learning, which would explain Trader Scott experience with shooting instruction, and also determine the higher level of achievement. However, I don't think they would give an edge without enough training.
A smart student can go faster and further than a less gifted one. However, if he doesn't work toward it, he will not go anywhere. It is fairly easy to notice that smart student grasp the basics very fast, which give them a pretty good start. However, in the long run, those who work harder to learn will have an edge. Obviously, the smart and committed student will eventually master the skill better and faster than anybody else.
Previous incarnations of the GDW house system have a more realistic approach to the task system. In Cadillacs & Dinosaurs, Dark Conspiracy and (I guess) T2K 2.0 characteristics didn't have any influence on the task roll, made with a d10. However, to buy a skill level over its controlling characteristic would require twice as many experience points. Not a bad system, although the reduced range of the d10 forced only three level of success (easy, average, and difficult). A good patch for TNE and T2K 2.2 would be include the higher cost to acquiring and taking out the characteristic value from the task roll. Skill values could be doubled or, when appropriated, two skill values could be added to some multidisciplinary tasks.
It is possible that my ideas are too centered in intelectual skills and thus are not adaptable to other areas. However, my personal experience with sports, martial or otherwise, tell me I'm not too far from the spot. Perhaps, some actions are performed more by instincts than skills, usually because there is not much to learn. In those cases, I would recommend not to use any skill, and keep only the characteristic.