Here is a suggestion to slim down the time line even more. I wrote about it on the kickstarter page but thought it would be better here :)
To make the animation repeat/pingpong = right click on play-button and choose it.
Scrubbing with middle mouse button or similar in the animation area to be able to iterate faster. Ex. hold down middle mouse button + move left/rigt to move in the timeline.
pic on a slimmer timeline:
What do you think?