General Presidential Pardon info;
Just to kind of consolidate information:
So-called 'pre-emptive' pardons are for PAST CRIMES that may be discovered in the future. Cannot pardon for crimes that may be committed in the future.
POTUS can pardon whomever he wants for whatever FEDERAL crimes he wants, up to an including murder, insurrection, or treason. There is no restriction or oversight. There is a 'presidential pardon cmte', but they are advisory only.
'Self-pardon' has never been tested. There are arguments for both sides. Nixon considered it, but resigned and let Ford pardon him.
A Presidential Pardon does NOT erase a conviction.
A Presidential Pardon is generally held to be irreversible by either Congress or the courts. The only time one has been reversed was when it was granted and then reversed by the same POTUS. Whether or not a POTUS can reverse a pardon granted by a different POTUS has never been tried.