The brilliant thing about the first example is that differentiating "important" items with the icon actually allows multiple forms of categorizing items in the list, whereas your suggestions only allow one. The items in the list are grouped by topic, and important/common ones are highlighted with an icon. Hiding the less important options makes them needlessly harder to find if/when you do need them. Moving important items to the top breaks the topical grouping. In both cases, the application becomes less discoverable.