Does taking medications for fever/sore throat (acetaminophen, chloropheniramine) help reduce it's duration? What if I do not take any medication?

No. These medications do not shorten the duration of a sore throat. Their intent is to make you more comfortable while you wait for it to pass.
No. Unless you sore throat is from sinus drainage, anti histamines will not help. Tylenol (acetaminophen) helps with symptoms but does nothing to alter the course of an illness.