Tween issues:
As you move from blocking to setting up tweens watch your library.
If you get a tween 1 tween 2 etc in the library it is due to the software making one of your assets into a symbol instead of you controlling that ahead of time.
Make sure all of your assets are symbols.
Make sure they are all on the main timeline if that is where you are going to animate them.
Rotation issues:
Rotation Issues generally come when you are trying to do too many things like rotating and flipping.
Do one at a time. One timeline keyframe at a time.
If you have a rotation that goes opposite the spin you want you can tell it to go clockwise or counterclockwise in the spin in Properties > Tween > Rotation > choose auto or clockwise or whatever works for your spin.
If that still does not work break up your timeline in smaller segments - rotate about 30 degrees then rotate further, then flip the asset.
Contact Susan if you are stuck.
Animation Test by Lindsay Poulos - Check out her funny "Animation Fail" - thanks Lindsay for showing us your example! and no she did not fail. We will look at how not to do this from the beginning. (Do not animate until rotation points are set)
Solve by creating columns for between character key poses
by Danielle Cowell with Hair Whip pose
Animating the Rig Below
continued below in Part 2
Danielle Cowell - Rig Layout
So the key to making sure your rotation points don't go all over the place is to set them before putting any keyframes in.
This is a part of the rigging process before handing it over to the animator.