Couple of comments:
In your dio, I think the composition and stances of the figures you've decided on work fantastically. May want to alter the leg position of the fallen gundam a little bit to create more drama, but the hands thrown in front for defense are just superb. Second, I hope that the finish you've achieved in the first three pics in the above post is something you will apply to the dio, as it's just great.
For damage: The two open areas that I saw, that is the shoulder and foot of the fallen gundam require more 'gizmology' Tear open some piece of electronics that you no longer need and get some circuitry from there in the form of transistors, resistors, all softs of stuff. Get different gauges of wire, and just throw in as much as you can in there. A machine like a gundam is bound to have a boatload of machinery, hydraulics, and other systems behind that armour, so you have to demonstrate that. Now, I'm assuming any removal in such a violent fashion would have created some kind of mild explosion, maybe fire, smoke in the least, so when you paint it, you will want to incorporate a little bit of shading to darken and burn the areas around the missing limbs. Some cracked paint wouldn't hurt either, as at the base coat, all metals are 'metallic' (duh) in colour, and severe damage like that would not just leave the adjacent areas unaffected.