Hi Lou, thanks for your point. I understand.
In your specific situation I think I would just finish it in TVP.
Next time, if you have animation partially done from elsewhere, I suggest you import at a rough state, so you can use Animation Paper to do additional timing and clean up.
Making new animation from scratch using Animation Paper is of course best, if you like the simplicity and focus it offers. As you seem to agree with. Uncluttered and unbloated.
The technical reason you can’t just alter your imported png’s or jpg’s is because they are bitmap/raster images. Animation Paper internally holds more sophisticated data for each drawing – which gives you various advantages. Like better color fills (coming soon), scalable drawings without degradation and more advanced features coming in future releases.
I hope I made sense. 😉