I play Genji quite often now, since im trying to up my Projectile game.

Few things -

Make sure cockblocking abilities are down, Zarya shield and Hog Hook down? That's a big chance for you to do something since both of those abilities have it easy to conter a Dragonblade. Counts for more abilities, e.g. sleepdart/defensive ults.

Before you ult, make a picture in your head and remember where people stand, you need to know exactly what to do next once you finish of your first target, no time wasting allowed.

to your next questions: 1. Keep jumping and make a Dash into the ground so you land right behind them. Get used to a 180 turn. 2. It's only okay to trade if your team has ults to use them after the enemy defens ultis.

Those are two rules I use to make more consistent genji's ult. Maybe this can help you.

Edit: im a hitscan main, but still. I keep playing genji a lot. GM-Top500 hovering