Nose repair options and advice?

I have the original "flexible" nose / bumper skin on my Black '81. Like many, I have several rock chips and scratches there, so I am considering either repainting the entire nose piece or touching up all the chips and carefully sanding and polishing the repairs back into conformity. The care was repainted in '93 by the previous owner with a pretty cheap paint job. I'd appreciate opinions on:
1) How hard is it to sand and polish the repairs to get them totally blended in, or at least as close as possible?
2) Do you suggest any primer or anything under chips that are between the size of a dime and a pencil eraser?
3) Flexible additive to the paint for such small repairs?
4) Other advice?

Hello Chesh,

If you have Dime size chips on your bumper, the last paint job did not get the flexible additive or the bumper was not prepared properly. It would be best to sand and re-prep and paint the entire bumper. In the end you will be much happier with the result, as brush painting and sanding large spots will be difficult at best.

Alex