Yeah, exactly.
This is the first I've heard about the Anakin body stealing thing though. As far as I know, Palpatine just wanted to groom Anakin to be his enforcer. As the chosen one he was supposed to have been exceptionally powerful before Obi-Wan messed him up, and getting stronger. That Vader was able to hunt the Jedi to near-extinction after suffering crippling injuries, all while sealed in what amounted to an ungainly mobile life support system, speaks to his terrifying potential.
Palpatine probably would have become absolutely unstoppable with a fully mature and loyal Anakin at his side.