Lubricate Loaded Calipers? Brakes dragging intermittently

So should the pad that sits against the piston should just slide freely inside the caliper without and lubrication? It certainly doesn't move freely so perhaps I do need to file down the edges....I thought some silicon brake grease might get me there as well. I'll try to figure out how to get that outer pad locked down by bending the tab. I really don't think my clearance between my booster push rod and MC is off because it's not locking up consistently.