does vomitting break fast. 2) is wiping the neck a part of wudu. Please provide references.

Q: Kindly explain when does vomit invalidate fasting.

A: The Fuqahaa have explained different types of vomit. We hereby simplify them as follows: Uninduced (involuntary) or induced. Each of the two could either be mouthful or less than a mouthful. Thus, there exist four possible cases: (a) Uninduced - mouthful, (b) Uninduced - less than a mouthful, (c) Induced - mouthful, (d) Induced - less than a mouthful.

The vomit in each of these cases could either: a) Exit from the mouth, b) Unintentionally swallowed, c) Intentionally swallowed.
Only two situations invalidate the fast, a) Uninduced - mouthful - intentionally swallowed, b) Induced - mouthful irrespective of whether it is swallowed or not. (Darse Tirmidhi vol.2; Darul Uloom Karachi)

It is Mustahabb to wipe the neck in Wudhu.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai