Scrolling speed is very custom kind of thing. Your going to need to figure it out. however here is the basics.
If( layoutscale != endScale )
layoutscale = lerp( startScale, endScale, lerpValue between 0-1)
and for scrolling
My suggestion is to
make a camera target object
make a camera object. Attach ScrollTo behaviour to the camera object.
move the camera target object to where you want.
if camera target is not overlapping camera object
cameraveObject.moveTowards XY of CameraTarget of speedInPixels * dt