You do realize, don't you, that the federal courts have, with the exception of two circuits (and the Supreme Court smacked down the reasoning used by Judge Posner in the 7th circuit - so it really means only one circuit is an exception), found that using the courts in a private suit constitutes government action because the judiciary is part of the government. In other words, the Federal RFRA would be applied in the same exact way as the Indiana RFRA would - as a defense raised before the court because the court could not rule on the case because it would involve government action in contravention of a person's sincerely held religious beliefs? The Indiana version merely codifies this rule. So no real difference here. This one issue swallows both of your "differences" because 1.) The government becomes an actor once it comes to court and 2.) The Federal RFRA becomes essentially an affirmative defense because of #1.
Actually, IMHO, the Indiana language raises a serious "Entanglement" question. Of course, the law in its present form is untested; so we have no idea whether that will be the case (no pun).
But, the Term of Art "Intervene" is used, as it is in a Federal False Claims Act ("Qui-Tam") case, not to refer to the Judiciary performing its usual duties of "interpretation"; but rather when the Government actually becomes a PARTY to the case-in-chief (in the case of the FCA, the Plaintiff, and in the case of RFRA, the Defendant(?)). Otherwise, the Government would ALWAYS be considered a Party in EVERY case, and of course that is patently ridiculous.
And besides, it is clear by the plain language of the IRFRA that it is primarily intended to be used as an Affirmative Defense not by the Government; but by the "real" Defendant(s).