The scroll I just place a ScrollTo Behavior in the player mask.
The effects of transition from one room to another, I did using a global variable that indicates where the player came in and then shows where it should go and where to appear :D
another thing, I'm having a mega work to create alternatives to mask some objects, because it could not do Construct2 detect the collision of sprites without taking transparent pixels.
an example is, I have a sprite 150px x 150px, but only in the middle of it that actually has pixels that are not transparent, the rest is all transparent pixel.