I managed to create a copy of the Colossus attack, but copying and properly linking all of the related actor data is not automated and is concequently a huge pain.
Edit: Lol, I just noticed my Battlecruiser's rank goes up with kills (as flavor text only). Is that new?
Edit 2: There doesn't appear to be a way to determine what item is in a specific equipment slot. The first item you pick up is considered to be in inventory slot 1 wherever you actually put it. This is a big problem for my plans

There's an unused Acid Spores ability in the game: