Is there a way to sand this down and paint it flat black?

Or whould it look like shizzz?

 

you could peel off the loose chrome and go after the rest with a scuffpad and remove the shine off the chrome to paint it, But it will probably look like crap.

Your best bet would be to look on bay of another place for a replacement grille.

 

If you have the time you can sit there and peel it all off, may need a little help from a razor blade, then sand it smooth, and paint and you will never know it was chrome. But this takes time and paitence.

My suggestion is save your time and buy a black grille from ebay, they are around $30 and then scuff and paint that one,