1) Dead is dead (A&E). So by their own rules, Rumple is NOT dead!
2) His living definitely doesn’t lessen his sacrifice. He killed – or attempted to kill – his father and himself. That’s HUGE…no matter how dysfunctional, a child loves their parent, even one that’s as wretched as Malcolm/Pan. And Rumple showed that he still loved his father, just moments before, in his shop. But he was willing to kill the man to save Belle, Bae, and the entire town.
Sacrifice doesn’t need to mean death, it could mean any number of things, especially for Rumple. To be powerless, after being the Dark One for so long, would be a fate WORSE than death for Rumple. So maybe he’s completely lost his powers, or maybe he’s being controlled by the WW and needs to be saved…but I definitely do not think we need to worry about Walking Dead Rumple. 🙂