I don’t think Regina’s death or disappearance could be the trigger for the destruction of Storybrooke, though. Unless Regina snuck something in without Rumple’s knowledge (seems unlikely, since Belle’s about the only thing she’s ever been able to “beat” him with), he would know that hurting her would put himself and Belle in danger–and he would never have summoned a wraith on her.
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Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing