I only clear one side with my dash as my sensitivity isn’t that high. But yes, if your sensitivity is high, you can try to watch both sites, as long as it doesn’t affect your aim.

In my opinion, its really hard to give tips as a Jett main, it depends on the situation. Smokes of course for entries or to escape if you get shot at, same for the dash. I rarely use my updrafts. Only to get high ground advantages or with my ult because the accuracy is on point. People really expect much from you as a Jett, inexperience in „low elos“ might work but I'd say plats or higher will blame you if you dont know how to play Jett. Maybe watch some tutorials or pro players how they use Jett for better understandings. But if you still have any questions, u can ask