In the Timeline view, you can easily drag keyframes to change the animation timing, delete them, cycle them and even copy them.
When you have position keyframes set in your drawing layer and you want to move them around when moving your drawing's timing, you can use the Paste Special feature to only move selected keyframes.
You can also use the Paste Cycle and Paste Reverse feature to cycle your selection including keyframes and drawings.
If you want to cycle a portion of your animation, you can use the Paste Cycle command. You can also use the Paste Reverse command to completely reverse the flow of your animation.