Ruling on someone who abandons Salah

Q 1: I read in a book about the ruling on the person who does not offer Salah (Prayer) that they are considered Kafirs (disbelievers) and are neither allowed to marry a Muslim, be buried in the Muslim graves, nor even be offered Funeral Prayer when they die. If a person is heedless of Salah and some religious rulings during a certain time in their life, will they be considered like any other sinner or are they regarded as Kafirs?

A: The person who deliberately abandons Salah is a Kafir according to the most correct opinion of the scholars regardless of whether they deny its obligation or not. However, if they really deny the obligation of offering Salah, they are Kafirs according to Ijma` (consensus of scholars), for the Prophet (peace be upon him) said: What makes one a Kafir or a Mushrik (one who associates others with Allah in His Divinity or worship) is abandoning Salah. (Related by Muslim) The Prophet (peace be upon him) also said: That which differentiates us from them (i.e. Hypocrites) is (our performance of) Salah. Anyone who abandons it becomes a Kafir. (Related by Imam Ahmad and Ahl-ul-Sunan [authors of Hadith compilations classified by jurisprudential themes] with an authentic Sanad [chain of narrators]) Allah (Exalted be He) says about the dwellers of the Fire: "What has caused you to enter Hell?" They will say: "We were not of those who used to offer the Salât (prayers), May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.