The pad paste goes on the back plate of the pad, where the metal pad housing touches the caliper piston, get some brake cleaner- spray can $2 and spray the housing and caliper before installation. It evaporates quickly and should dissolve the caked up brake dust.
Also use the brake cleaner to spray the plate behind the rotor and clean things up. The ABS sensor is around there and if cleaned should work ok. They mostly just need cleaning... in my experience.
Dont spray the brake pad with cleaner.... just everything else.
Clean the slide pins that hold the pad with emory cloth, sand paper.... or something, and apply a small amount of wheel bearing grease to the pins.
If you are still running semimetalic pads .... you will get an occasional squeek.
If the rotors have any grooves worn into them the squeek will be more frequent.