If Obama wore a crown, he'd have a lot easier time getting his program through Congress.
The Presidential pardon question is interesting. I doubt that Clinton will be indicted for anything; at worst, there might be some kind of misdemeanor agreement that she failed to secure documents and promises not to do it again. But there wouldn't be anything to stop the President from pardoning her, and anybody who works for her.
Bush I pardoned half-a-dozen Reagan officials, including the SecDef, accused of Iran-Contra misconduct.
http://www.internationalskeptics.com/forums/newreply.php?do=newreply&p=11344320
Clinton pardoned big contributor Marc Rich, Whitewater figure Susan McDougal, ex-HousingSec Henry Cisneros, and CIA Director John Deutch.
Obama could easily say that after reviewing the matter, he's determined that Clinton had no criminal intent and did no harm to U.S. interests, and that therefore a pardon was appropriate. I don't even think it would hurt her much against Trump.
That would cost her the election. I would never vote for Hillary under those circumstances. I doubt I'm unique. On the other hand, Republicans would crawl over broken glass to vote against pardoned Hillary Clinton. Turnout on their side would probably be universal.