About the chipping, that green is painted over the underside color, that underside color is painted over a red oxide colored primer. Most likely, or at least most people who have studied Zeros, agree that the light colored chipping is the underside color, not bare metal. The protective color (seen on the underside) was pretty glossy and durable. The idea is the the green paint didn't stick to well to it. On the cowling the bare metal is ok.
The over-chipped Zeros you see photos are almost always damaged derelicts from bombing and strafing raids. Or, if still in service and chipped badly, they are field painted, not factory painted. At least that's what I get from looking over photos.
Other late war planes, like Skyraider brings up, were painted green over bare metal, no primer, and that chipped. But Zeros not so much.
It's your call since this isn't 100% verifiable, but I'd urge you to change that chipping from bare metal to the underside color .
Speaking of color, your underside might be a bit bright/light.
Overall, it's looking really nice! It's always good to see upper/lower views with the profile too