The Godot game engine has some really powerful 2d animation tools. It's completely free and open source, and its original creators used it for 2d point-and-click adventure games with lots of animation.

Here is some documentation on its animation features:

• Animation intro
• Cutout animation
• 2d skeletons

You would have to make your animations as a "game" and then record video/take screenshots, though, so it might be overkill.