Can Obama be indicted if he's implicated in the DOJ's investigation of the phony Russian-Trump collusion investigation?

A jury conviction in a criminal case takes a unanimous decision by a jury of 12, and an unbiased judge to oversee the trial, and an unbiased court of appeals, and an unbiased prosecutor, and an unbiased media not wanting to put their hand on scale of justice.

The chances of all of the above in a case against a high profile politician still loved by so many is about ZERO.

OJ Simpson only had some of the above and the jury treated him as a victim of malicious prosecution.

They would have to prove a crime. And I would say that the idea of indicting a former president of the United States would upset a LOT of people. A lot of very rabid extremist people.

I suspect he can be if it can be shown that he knowingly initiated a spying/disinformation operation against a presidential candidate.

To indite the messiah it would have to be very serious and then there would definitely be a civil war.

Probably not.
Whatever happened while he was in office would probably fall under executive immunity

Not if you can't spell it.