I cleaned the top of mine with Armorall wipes-in the yellow container. It was never really dirty so it worked great. Sounds like you can use a wire brush maybe to loosen that stuff up, but the top of the SC is metal right? Sorry, don't have one myself.
Wipes wouldn't work on metal. I'd get a steel wire brush and brush it off. But I don't know exactly what kind of sh** is built up on it. Wish I could help more. If anything else I'd just get Simple Green degreaser or other cleaner and try it out.
As far as hood chips, I have only touched up spots, and you're right it does look like little bumps of paint. Very noticeable. I wanted to sand the front of my hood and repaint it but since my brother hit my car, the body shop will blend my hood and repaint it (most of it) this week.
The last time they fixed my car, they matched the paint perfectly and it wasn't too noticeable the difference between the old and new paint. I haven't done any blending of paint yet, but if you do light coats and blend it into the old paint, sand it and use rubbing compound.... it should look pretty clean and uniform.
I think I'll try mine, if they don't paint the whole hood. And I'll let you know how it goes.