How to use timewarp

First, time warp starts working on the in point of the source footage. You will have to deal with that when you select a clip in a Premiere Pro Sequence and select Replace With After Effects Composition in the timeline. It is easy to do if you pre-compose the footage layer. Here is a step by step:

1. Inside the Premiere Pro sequence select the clip you want to move to After Effects and select Replace With After Effects Composition from the menu (it will be one of the options in the popup when you right-click on the clip)
2. When After Effects opens up, save the file and then make sure you open the Composition that was created by Dynamic Link
3. Select the footage layer in the timeline and Pre-compose making sure you move all attributes to the new composition
4. Apply Timewarp to the pre-comp
5. If you slow down the clip you do not have to change anything in the nested comp
6. If you speed up the clip you have to open the Pre-comp, open up the comp settings, extend the duration of the comp and then reset the out-point of the footage

Extending the comp is just a matter of math. If you are speeding the comp up so 10 seconds take 5 seconds to playback the Pre-comp needs to be twice as long as it originally was. 

That should be all there is to it. I just explained this in another thread that you created. It's not hard. You just can not leave out the pre-comp unless the first frame of the clip is the first frame of the source video.