Pronation is where the arch of your foot is flat, rather than curved upward, and so your foot and ankle tilts inward. It isn't "bad," but it means you need proper support for it, otherwise you will have trouble holding an outside edge. You cannot diagnose yourself with pronation--you have to have a coach or a foot specialist determine it. If you do pronate, there's plenty to be done. There are exercises you can do to strengthen your ankles, or you can add padding inside your skate to counteract the natural lean of your foot. Shifting your blades is kind of a last resort.
Since I pronate, when I got my custom skates made, I ordered special hooks on the tongue. When I lace up, the laces twist around the hooks. It does an excellent job of keeping the tongue from shifting.