Resistor and capacitor footprint sizes are most often dictated by the circuit design requirements for power and voltage. I would consult with your design engineer before making any footprint size changes.
Changing that .01uf capacitor from a 1206 to a 0402 may seem like a good thing to do from a pcb design perspective, but that size change could be taking a 600 volt rated part down to a 50 volt rated part and that would not be a good thing if the circuit required a 600 volt part.
If the person designing the PCB is NOT the same person that designed the circuit, the pcb designer must consult with the circuit designer before making any changes.
I had a designer one time make some changes to a circuit design I did because it "made routing easier". Needless to say, he had to redo the board which wasted a lot of time and money.