For the stairs , you may be able implement a step up type feature. (Although I am not sure how one would achieve such a thing in Construct)
When going to the double jump room, I ended up going from the top where the roll ability is which is why I was confused. As a solution to this, you could either remove the enemy, or structure the room so that the enemy is on an elevated box. You could also make the room to the left's top platform leading in at a height so that you would need double jump as well as make the bottom roll corridor of the room to the top left go farther left. This would make it so you would have to go in from the bottom.
Finally, I always ended up going to the right first at the start of the game (Which I had to do twice due to the fact that pressing R resets the game.)