2011 with 130k km on a dash. Strange that your KYB bearing was making noise. It looks like it got plenty of grease inside. Unless KYB plastic is even softer and that allows even more deformation. Greasing old bearing sorted all noises for me.
Does green light with vehicle symbol comes ON on dashboard? If not check for fault codes. If you don't have LeafSpy app and obd adapter or there is no fault code, then most likely your brake pedal sensor is faulty.
You probably refer to them holes on lower bearing part. It's not for bearing balls as they are to deep. These holes are designed to store grease and grease middle part while it's sliding. No there is no looseness in it. It looks perfectly fine. I can't even see much of blue plastic dust which...
I had similar banging sounds for a couple months now. It was worst when driving in reverse and turning steering wheel. It sounds like spring gets bit of tension and then suddenly releases. This indicates bad strut bearing. So I ordered a new one and took everything apart today to change strut...