1. Due Process:
Due process is a judicial constitutional guarantee that no judgment can be made without a just legal proceeding. The Constitution guarantees that the government cannot take away a person's basic rights to 'life, liberty or property, without due process of law.' Courts have issued numerous rulings about what this means in particular cases.
Fundamentally, due process of law means fairness. Fairness is ensured through the procedures where all people involved are given an equal opportunity to tell their story. Due process includes the rights to (1) representation/legal counsel, (2) confront and cross examine the witnesses, (3) refuse self-incriminating testimony (pleading the 5th), and (4) have a crime proven by proof beyond a reasonable doubt.
All laws pertaining to student discipline are written with the general goal of ensuring that students receive due process of law. This includes the following fundamental rights, especially as it applies to suspension or expulsion:
Timely notice of the reasons for the discipline;
An opportunity to prepare a defense;
An opportunity to present a defense;
The right to be represented by an attorney;
The right to a fair and impartial hearing;
The right to examine witnesses and present evidence;
The right to an impartial and fair decision (without personal bias);
The right of appeal

2. Amendments in Question
Amendment I
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.
Amendment IV
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Amendment VIII
Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted.
Amendment XIV
Section 1. All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside. No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

3. Separation of Church and State
Here are some interesting facts…
"Separation of church and state" is a common metaphor that is well recognized. Equally well recognized is the metaphorical meaning of the church staying out of the state's business and the state staying out of the church's business.
Because of the very common usage of the "separation of church and state phrase," most people incorrectly think the phrase is in the constitution. The phrase is not in the constitution. The 1st amendment of the constitution reads that “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof…” Both the free exercise clause and the establishment clause place restrictions on the government concerning laws they pass or interfering with religion. No restrictions are placed on religions except perhaps that a religious denomination cannot become the state religion.
The phrase "wall of separation between the church and the state" was originally coined by Thomas Jefferson in a letter to the Danbury Baptists on January 1, His purpose in this letter was to assuage the fears of the Danbury, Connecticut Baptists, and so he told them that this wall had been erected to protect them. The metaphor was used exclusively to keep the state out of the church's business, not to keep the church out of the state's business.