Would a recruit for the United States Marine Corps be turned away for self harm?
Self harm is when someone intentionally causes injury or pain to themselves. Self harm is almost always related to a mental health condition. Those experiencing mental wellness related illnesses cannot join the Marines.
The answer is yes.

Has Freemasonry been represented on the Moon?
Freemasonry is a group of fraternal organizations rooted in fraternities of stonemasons of the fourteenth century. Buzz Aldrin was initiated into the Freemason fraternity in 1955. Buzz Aldrin and Neil Armstrong were the first men to land on the moon in 1969.
The answer is yes.

Gandalf hypothetically defeats Rincewind in a wizard battle?
Gandalf is a 2000 plus year old wizard that has fought orcs and spirits in Middle Earth. Rincewind is the protagonist of the Discworld series. Rincewind is a failed student at the Unseen University for wizards in Ankh-Morpork. Rincewind is described by other wizards as the magical equivalent to the number zero.
The answer is yes.

Is myocardial infarction a brain problem?

Myocardial infarction is a problem in the heart. The equivalent in the brain would be similar to a stroke.
The answer is no.