I like to create roto shapes without animation keys. With the "auto key" button disabled I'm able to create new shapes, but the vertices cannot be edited. Editing seems only be possible with auto key on, but then I create a key frame which I like to avoid.
Another issue in this context is that when pressing "remove all animation for the selected shapes(s)" on a shape that already has no key frames set, all vertices collapse to the lower left corner.
PS: Even though I use this forum mainly to report bugs which might sound like "I'm only complaining", I like to mention at this point how awesome I find Natron. Doing compositing for over two decades now (mostly on Nuke), switching to Natron for personal endeavours was a no-brainer. Keep up the amazing work!