1.The Establishment clause prohibits the government from establishing a religion. What constitutes the establishment of religion is governed by a three-part test that was established by the supreme Court in the Lemon v. Kurtzman case in 1971, this is the Lemon Test.  The Establishment clause was established to make sure that the government cannot impose, force, or promote a certain religion, and if a governmental law or action is allowed to promote a particular religious practice, it must pass the Lemon Test which are, (1) there is no excessive entanglement between the government and the religion, (2) the assistance must neither promote nor inhibit religion, and (3) the primary purpose of the assistance is secular.

2. Burning of the US flag is protected by the First Amendment under the freedom of Expression. In 1960, during the Brandenburg v. Ohio case, the supreme court ruled that Symbolic speech  was subject to the same the protection as written and spoken communication. So, in 1989, during the Texas v. Johnson when Johnson charged with desecration of a venerated object after Burning the US flag during a protest in 1984, the Supreme court found the law as unconstitutional stating that burning the flag was a form of symbolic speech protected by the First Amendment.

3. When someone says, “I’m taking the Fifth, ” they are exercising their fifth amendment right to not self-incriminate by remaining silent. The person’s silence cannot also be seen as an admission of guilt or used against them in their trial.