I do not think POTUS can pardon anyone not indicted/convicted of a crime. Hillary scated free with no indictment with help from Comey & Lynch.
“I do not think POTUS can pardon anyone not indicted / convicted of a crime.”
Yes; he can. Ford pardoned Nixon. No indictment or conviction.
See the US Supreme Court decision, 'Ex Parte Garland':
Pardon power "extends to every [federal] offence known to the law, and may be exercised at any time after its commission, either before legal proceedings are taken or during their pendency or after conviction and judgment."