I believe the IG is limited in the Scope of his Investigation and Report. Seems like too many are climbing aboard the IG train blindly. Meanwhile Trump seems to be stirring the pot rather well. Sessions has no drive to help. Trump will get his WIN. Many will lose jobs and respect. Very few will be actually charged with anything. The Freepers that are in Sessions corner as a GOD of some type will be trying to cling to Trump. Trump is Winning despite Sessions. The IG will help but it doesn’t really matter.
According to the IG website, the scope of the investigation is limited to DOJ and FBI actions taken during the Hillary email investigation. I believe the investigation also covers various leaks. So all the other stuff would appear not to be covered.
About Horowitz, he's definitely an Obama appointee. I've also seen charges that he's a Barney Frank protege and that he white washed the Fast & Furious investigations although I've not come to any conclusions on those two charges.
About the Nunes, Goodlatte and Grassley committee investigations, I have more confidence in them than I do in the IG investigation.
The biggest question remains however. Who will prosecute, anything? Sessions IS recused on all issues related to the campaign, Hillary and anything connected to all of that. That leaves swampster Rod Rosenstein in charge.
So good luck with that.