He wants a mix of skeletal and frame-by-frame animation.
Some interstitial poses simply can't be done without image swaps (or bringing in entire sequences from another program) or completely changing the setup of the entire skeleton.
johnnygalvatron's use case is a bit simpler, I think. But I'd love to see support for this that rivals UbiArt and Vanillaware's system in Muramasa.
@johnnygalvatron:
Just export the image sequence from Flash into your project folder, then add them into your Spine project. Put all the frames into one slot in your skeleton/project.
To animate it, right now, you'll have to animate the individual frames one by one by swapping and keying slot images one by one.