Complex animations (Unity 2D)

Hello!

I am asking this from a Flash background.

In Flash it is very easy to do morphing, filters, etc.
So for example, you can create a dynamic scene where you can just place some characters and control their animaton, body movement, breathing etc all individually.

All of this, without taking too much space on the final product.
Yet in Unity it seems to be the opposite. Huge file sizes because you have to do tradional animation with each frame drawn out after one another.

Is there a way to do this I am not seeing or some plugin that brings the funcionality to make it on par with Flash animation?

Yes, it is possible to do bone animation and position / scale tweens through the Unity Animation window. However, compared to Flash, this is definitely quite limited. There are a few plugins that make this significantly better though, I would highly recommend Spine.

Alternatives to look at might be SmoothMoves, Puppet2D.