Does it mention about - 1. Marriage of Shiva & Parvati 2. Birth of Kartikeya & Ganesha 3. Consuming poison during churning of ocean 4. Birth of Andhaka Or some other events? I know Mahabharata mentions about the destruction of daksha sacrifice by veerbhadra, but it doesn't mention sati & all that (just like other puranic stories). Bhagwat gita 10th chapter mentions about kartikeya & gives a hint of samudra manthan while describing about Ucchaishrava horse. Please give reference from accurate versions of Mahabharata.
Mahabharata: Adi Parva: Chapter 62 mentions:
This work [Mahabharata] presents an account of the gods and royal sages and sacred regenerate Rishis, the sinless Kesava; the god of gods, Mahadeva and the goddess Parvati; the birth of Kartikeya who sprang from union of Parvati with Mahadeva and was reared by many mothers; the greatness of Brahmanas and of kine.
The story related to the birth of Kartikeya can be found in Mahabharata: Anusasana Parva.
Consuming poison during churning of ocean can be found in Mahabharata: Adi Parva: Chapter 18:
But with the churning still going on, the poison Kalakuta appeared at last. Engulfing the Earth it suddenly blazed up like a fire attended with fumes. And by the scent of the fearful Kalakuta, the three worlds were stupefied. And then Siva, being solicited by Brahman, swallowed that poison for the safety of the creation. The divine Maheswara held it in his throat, and it is said that from that time he is called Nilakantha (blue-throated).
Similarly, there are many stories related to Lord Shiva and Parvati in Mahaaharata.