Well for the wings you would need to seperate them for a good effect and use some cframe offset math with angles, but off the top of my head I gues you could mess about with scale to make them seem like they are fluttering but it might not look right, your probably better off waiting for the new bone mesh deforms to come out so you can just have a looping animation.
What do you mean by “rotate the mesh backwards?” You’ve just taken a screenshot of your character with wings on them but you don’t specify what it should look like.