Hi,
PlayMaker doesn't produce scripts out of your Fsm. it simply leaves in the PlayMaker Fsm component attached to the gameObject ( or in templates assets if you use them).
So simply export your GameObject ( as prefabs likely), and you can import them in other projects.
don't forget that Unity will not detect if you are using custom actions, so don't rely on Unity dependancy check if you import a lot of assets. you will need to manually add to the package your custom actions. For this, I have a very simply way out. I put ALL my custom actions in one folder ( PlayMaker Custom Actions), and I always include that folder when I export prefabs using playmaker, then I am safe.
As for backup. Back it up just like you want to back up your meshes or your scenes, it's a regular Unity asset.
bye,
Jean