The outside of the lid and firebox might clean up a little bit, but you might be left with the burn marks. Try some Simple Green on it with a sponge or cloth. You want to be careful not to damage the paint. That is one of the issues with these later generation grills. The grill boxes are no longer black, and there isn't a color matching high heat paint that I am aware of. On one that I did, the paint was actually flaking off so I did a color change to black on the bottom grill box and the end caps.
The FBs are heat deflectors are fine. Just give them a good soak and scrub. The FBs could actually be scraped with a putty knife. Be careful on the heat deflectors to not scratch/chip the porcelain. Back to the FBs, they are never going to be shiny again. That discoloration is due to heat. If you bought a brand new set, they'd look like that after a could of cooks.
Personally, unless you are super anal/ocd, I wouldn't spend too much time of effort cleaning anything I see in those pics. Just knock off the loose stuff, hose it down, put back together and start grilling.