Regionally manufactured materials

1) Where did the non-FSC material originate? Are you talking about wood products from a forestry operation? If so, you can count this material if the forest it comes from is within 500 miles of your site. Or are you referring to "reprocessed" wood salvaged from other sources? In that case it should count towards MRc3 (Resource Reuse) AND towards this credit if it's previous location was inside the 500 mile radius. If the material originated outside that radius, you're out of luck for this credit.

2) Radiant barrier sheathing is not typically made of recycled, salvaged, or FSC-certified material, so the only way I can think of that it might contribute to earning LEED points is by helping save energy and contribution to EAc1. It's not possible to say how many points that particular product will earn you unless you run an energy simulation with standard sheathing and another with the radiant barrier (assuming that your software can even model the radiant coating's effect). Based on the energy cost savings that the radiant barrier provides you can figure out how many points it earns you.