[Vizcaster]

You'd only want to sand if there are defects, and it sounds like you avoided that. Sanding metallic leaves wierd marks so you need to recoat before the clear. Try to avoid the temptation of one last light coat of the metallic, because it wont lay the sparkles down the same way as the wetter coats under it, and it will not look consistent. I'd say you're good to go with the clear.