Image editor doesn't need to have robust tools - it won't replace higly advanced external applications in the pipeline.
However...
Additional option for ghosting frames would be nice - when 0 is a frame being edited, I would like to see -1 and +1 frame almost transparent to know where origin/image points are, compared to one being edited. Also it would be nice to see how image points in current animation relates to image points in other animation. This is crucial to maintain cohesion between two different animations played one after another.
I don't know how You guys are managing to place origin in two completely different animations with different poses - for me it's a trial - error approach.