If Blackbeard removes your power do you regain the ability to swim?
Doubtful. I think to completely rip off powers from another Devil Fruit user like Whitebeard, he probably needs to be dead or will die in the process. Think about it if that weren't the case, then Blackbeard would have extracted the Mera Mera no Mi's power from Ace when he initially captured him. The thing would've killed Ace and that wouldn't allow for a situation where Whitebeard went to war with the World Government.