My 280z ac condenser is black, but a lot of the paint has chipped off with time. Can I LIGHTLY media blast the condenser and repaint it? If read this affects cooling. Would you use normal paint?

Can I LIGHTLY media blast the condenser

There's no way I would ever blast a condesor with anything. Lightly or not.

I'm no A/C expert, but since you didn't get any other responses...

You could lightly paint it, but no sanding. You could use a soft wire brush and wipe down the fins to remove loose debris.