The Emperor's Personal Guard would have above average skills and I can see how many of them could be recruited from an intelligence background. But, contra to Hollywood, the Men in Black (Presidental Secret Service) do not possess significant Intelligence backgrounds (they only have to assess threat and be able to move the prez to predetermined safe locations). I would see, the Imperial Guard forfilling the same function for the Emperor. Problem is that selection for the Guard is left to the Archdukes confirmed by Imperial Edict, as seen in 1116...
Behind the Imperial Guard there is the vast array of competiting intelligence agencies for the 3I has no Department of Homespace Security, save the INI which by virtue that the Imperium controls the space between worlds is immensely powerful but does not have a monopoly. Sometimes, I think a good analogue for happenings in the Third Imperium is Germany's 3rd Third Reich (with or without the unpleasant sides).
Behind the Imperial Guard there is the vast array of competiting intelligence agencies for the 3I has no Department of Homespace Security, save the INI which by virtue that the Imperium controls the space between worlds is immensely powerful but does not have a monopoly. Sometimes, I think a good analogue for happenings in the Third Imperium is Germany's 3rd Third Reich (with or without the unpleasant sides).