You don't need event 5 and event 2's condition should be a "System: Every tick" condition.
You want the player to go right every tick.
There is still a "friction" issue, due, I believe to the value of the deceleration platform property that does not apply when the player is in the air.
Also, I'd suggest you'd actually look at the "Auto-runner template" that you have access to when you start a new project.
You will see a recommended way to do a smooth auto-scroller.