I've almost finished a project with a lot of 3d layers.
The problem is that I want to slow a camera movement to take 2 seconds more in the middle of the video, so when I do it, everything that comes after should be pushed 2 seconds but i don't know how to do it.
Well I could simply expand every layer to move the key frames, but I'm sure is a better way to do it.
If you haven't already fixed this, try precomposing EVERYTHING and mving all attributes, then in the newly created composition, select the precomp layer and go to Layer>Time>Enable time remapping.
Then, create a keyframe on the Time Remap property that appears, but create the keyframe where you want the "slow down" to start. Then create another keyframe where you want the project to speed back up, and drag that keyframe to the right.
You may have to lengthen the composition and expand the layer to the end and drag the right-most keyframe on the time remap to the end as well.
Hope this is useful for you :)
"Owww even my shadow's lookin' good" - The Cat (Red Dwarf)