WD-40 is a self fulfilling kinda thing, it evaporates.
My rotors rust at just the slight hint of water; after washing I can see where I splashed water on them. They grind a little on the first stop (backing out of the driveway), but I never hear them again.
How many miles do you have on ur Mo?
Good call Homer.
I had a toy 4x4 that made a POP when the steering wheel was at lock and it encountered a bump. I think it was a limit bumper letting go.
I have the same noise as jaak were when you first drive it for the day (like after work) and apply the brakes the first time, it makes a clack noise, probably the pads sliding to their stop. The other noises you have????? Beats me. Maybe a pad change IS in order.