In complete fairness, the writers were struggling from the beginning to generate dramatic tension with all the rules Gene imposed upon them. Which is compounded by the fact that, on a show with a supersmart android, a guy with vision across the entire electromagnetic spectrum, a Klingon warrior, and the survivor of a hell planet, Troi's powers might actually be the most OP if used halfway-decently. In the example you just mentioned, she detected minute fluctuations in people's emotions from orbit. Pair Data's research and analysis with Troi's senses, and in principle the Enterprise should be impossible to surprise.