Ignore the timer as your only goal is not to hit anything while you are running after Archie.
To make sure that you don’t trip over the bike rack, swipe at the very last second before you are about to hit it because if you jump too early, you’ll fall right into it.
As for the slides and the swipes, you can time them the same way, but you can also extend your slide and your swipe indefinitely by simply swiping down, left, or right over and over again. You’ll stay to either the left, to the right, or in a slide position, making it very easy for you to avoid or to slide under obstacles.
Tap the screen with multiple fingers on one hand on each side when the game starts requiring you to tap faster. This will enable you to be able to tap at only half the speed that you normally would have to, making it very easy to beat even the hard stages with three star scores.