Pads are moving in the bore like you thought. Nothing to worry about. You should hear what a set of full floating race rotors with aggressive pads sounds like. You would think the wheels are falling off.
Waiting on 2019 GT500 2012 GT Vert Brembo - Stock-ish 2012 F-150 FX4 EcoBoost 4x4 406rwhp/522rwtq. The most powerful EB F-150 on the planet?
2007 GT-TSR/Stops/Turns/Custom Everything/3.4L Whipple Crusher/1000hp SOLD