Sorry we didn't respond to your post sooner!
In Spine you can box scale and drag the edges of the box:
Graph - Spine User Guide: Box selection
Currently you can only drag left/right or up/down. Do you find it useful to do other transformations? We could allow dragging both width and height at the same time or skew (dragging a single corner).
We don't have numeric transformations for box selections. You can do it in the transform fields (eg enter =*2), though it's not as powerful as we'd like it to be.
Tools - Spine User Guide: Numeric entry
You can blend between two animations at runtime or in the editor using preview. There's not a way to store the blending between animations as a separate animation though.
You could do it within a single animation. At runtime you could adjust animation playback to the starting part, the blending part, and the end part separately (eg using TrackEntry animationStart and TrackEntry animationEnd). Or I suppose you could cut/paste the keys into separate animations in the editor, though that makes further editing more difficult.
FWIW, when you have two poses, like the end of your first animation and the start of your second animation, and you want to add breakdown poses between them, the favor tool can be very useful.
