Pad and Rotor Replacement Question

[we350z]

Doing a brake job on my X for the first time in 10 years. Rotors are toast they have lost some of the silver plating around the outer edge. Pads look to still have some meat on the bone. I had planned on replacing with new Akebono pads. Do / should I really need to do that or should I save them for down the road?

If I can continue to use the existing pads do I still need to remove them to retract the Piston or is there some trick to doing that with them still on?

Also I can't remember how do you remove the retaining spring just pry it off with a flathead screw driver?

Thanks guys!