MB3 192b: Separating Attached Papers on Shabbos (340:14); Nullifying Vows on Shabbos (341:1)

Separating papers for a constructive purpose & ripping attached pages in a new book are both אסור מדאורייתא. Separating stapled pages.

Ripping a garment along it's stitching for a constructive purpose.

If a garment becomes entangled in thorns on Shabbos.

Nullifying vows on Shabbos is permissible only if it's for the benefit of Shabbos or a mitzvah (e.g. a vow not to eat something). Kol Nidrei on Yom Kippur that occurs on Shabbos.